Where Is The Low Side Air Conditioning Service Port

DR		HEATING & AIR CONDITIONING 24 - 1

HEATING & AIR CONDITIONING

TABLE OF CONTENTS

page

HEATING & AIR CONDITIONING

DESCRIPTION

DESCRIPTION - HEATER AND AIR CONDITIONER . . . . . . . . . . . . . . . . . . . . . . . . 1

DESCRIPTION - COOLING SYSTEM REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . 1

DESCRIPTION - REFRIGERANT SYSTEM SERVICE PORT . . . . . . . . . . . . . . . . . . . . . . . . 1

OPERATION

OPERATION - HEATER AND AIR

CONDITIONER . . . . . . . . . . . . . . . . . . . . . . . . 1 OPERATION - REFRIGERANT SYSTEM

SERVICE PORT . . . . . . . . . . . . . . . . . . . . . . . . 2

HEATING & AIR

CONDITIONING

DESCRIPTION

DESCRIPTION - HEATER AND AIR CONDITIONER

All vehicles are equipped with a common HVAC housing assembly (Fig. 1). The system combines air conditioning, heating, and ventilating capabilities in a single unit housing mounted under the instrument panel.

DESCRIPTION - COOLING SYSTEM REQUIREMENTS

To maintain the performance level of the HVAC system, the engine cooling system must be properly maintained. The use of a bug screen is not recommended. Any obstructions in front of the radiator or condenser will reduce the performance of the air conditioning and engine cooling systems.

The engine cooling system includes the heater core and the heater hoses. Refer to Engine Cooling for more information before the opening of, or attempting any service to the engine cooling system.

DESCRIPTION - REFRIGERANT SYSTEM SERVICE PORT

The two refrigerant system service ports are used to charge, recover/recycle, evacuate, and test the air conditioning refrigerant system. Unique service port coupler sizes are used on the R-134a system, to

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DIAGNOSIS AND TESTING DIAGNOSIS AND TESTING - A/C

PERFORMANCE . . . . . . . . . . . . . . . . . . . . . . . 2 DIAGNOSIS AND TESTING - HEATER

PERFORMANCE . . . . . . . . . . . . . . . . . . . . . . . 5 STANDARD PROCEDURE - DIODE

REPLACEMENT . . . . . . . . . . . . . . . . . . . . . . . 7 SPECIFICATIONS

A/C APPLICATION TABLE . . . . . . . . . . . . . . . . 7 SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . 8 CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 DISTRIBUTION . . . . . . . . . . . . . . . . . . . . . . . . . . 24 PLUMBING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

ensure that the refrigerant system is not accidentally contaminated by the use of the wrong refrigerant (R-12), or refrigerant system service equipment.

OPERATION

OPERATION - HEATER AND AIR CONDITIONER

The heater air conditioner are blend-air type systems. In a blend-air system, a blend door controls the amount of unconditioned air (or cooled air from the evaporator on models with air conditioning) that is allowed to flow through, or around, the heater core. A temperature control knob on the A/C Heater control panel determines the discharge air temperature by controlling an electric actuator, which moves the blend door. This allows an almost immediate control of the output air temperature of the system.

The mode control knob on the A/C Heater control panel is used to direct the conditioned air to the selected system outlets. Both mode control switches use electric actuators to control the mode doors.

On all vehicles, the outside air intake can be shut off by selecting the Recirculation Mode with the mode control knob. This will operate a electric actuated recirculation door that closes off the outside fresh air intake and recirculates the air that is already inside the vehicle.

The air conditioner for all models is designed for the use of non-CFC, R-134a refrigerant. The air conditioning system has an evaporator to cool and dehumidify the incoming air prior to blending it with the heated air. This air conditioning system uses a fixed orifice tube in the liquid line near the condenser outlet tube to meter refrigerant flow to the evaporator

24 - 2 HEATING & AIR CONDITIONING		DR

HEATING & AIR CONDITIONING (Continued)

Fig. 1 HVAC Housing - Dual Zone Shown (Typical -

Single Zone)

1 - Mounting Nut

2 - Passenger Blend Door Actuator (dual zone)

3 - Mounting Nut

4 - Air Intake Spacer

5 - Recirculation Door Actuator

6 - Recirculation Door Assembly

7 - Driver Side Blend Door Actuator

8 - HVAC Housing

9 - Mounting Screw

10 - Defroster Door Actuator

11 - Panel Actuator

coil. To maintain minimum evaporator temperature and prevent evaporator freezing, the A/C Fin Probe which is located in the evaporator cycles the compressor clutch by sending an A/C request to the JTEC which in turn processes this piece of information and if all conditions are met cycles the compressor clutch.

OPERATION - REFRIGERANT SYSTEM SERVICE PORT

The low pressure service port is located on the suction refrigerant line, near the accumulator. The high pressure service port is located on the liquid line at the passenger side of the engine compartment, near the condenser.

Each of the service ports has a threaded plastic protective cap installed over it from the factory. After servicing the refrigerant system, always reinstall both of the service port caps.

DIAGNOSIS AND TESTING

DIAGNOSIS AND TESTING - A/C PERFORMANCE

The air conditioning system is designed to provide the passenger compartment with low temperature and low humidity air. The evaporator, located in the HVAC housing on the dash panel below the instrument panel, is cooled to temperatures near the freezing point. As warm damp air passes through the cooled evaporator, the air transfers its heat to the refrigerant in the evaporator and the moisture in the air condenses on the evaporator fins. During periods of high heat and humidity, an air conditioning system will be more effective in the Recirculation Mode. With the system in the Recirculation Mode, only air from the passenger compartment passes through the evaporator. As the passenger compartment air dehumidifies, the air conditioning system performance levels improve.

Humidity has an important bearing on the temperature of the air delivered to the interior of the vehicle. It is important to understand the effect that humidity has on the performance of the air conditioning system. When humidity is high, the evaporator has to perform a double duty. It must lower the air temperature, and it must lower the temperature of the moisture in the air that condenses on the evaporator fins. Condensing the moisture in the air transfers heat energy into the evaporator fins and tubing. This reduces the amount of heat the evaporator can absorb from the air. High humidity greatly reduces the ability of the evaporator to lower the temperature of the air.

However, evaporator capacity used to reduce the amount of moisture in the air is not wasted. Removing some of the moisture out of the air entering the vehicle adds to the comfort of the passengers. Although, an owner may expect too much from the air conditioning system on humid days. A performance test is the best way to determine whether the system is performing up to standard. This test also provides valuable clues as to the possible cause of trouble with the air conditioning system.

Before proceeding, (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - WARNING) and (Refer to 24 - HEATING & AIR CONDITIONING/ PLUMBING - CAUTION). The air temperature in the test room and in the vehicle must be a minimum of 21° C (70° F) for this test.

(1) Connect a tachometer and a manifold gauge set or A/C recycling/charging station.

(2) Set the A/C Heater mode control switch knob in the Recirculation Mode position, the temperature control knob in the full cool position, and the blower motor switch knob in the highest speed position.

DR		HEATING & AIR CONDITIONING 24 - 3

HEATING & AIR CONDITIONING (Continued)

(3) Start the engine and hold the idle at 1,000 rpm with the compressor clutch engaged.

(4) The engine should be at operating temperature. The doors and windows must be closed.

(5) Insert a thermometer in the driver side center A/C (panel) outlet. Operate the engine for five minutes.

(6) The compressor clutch may cycle, depending upon the ambient temperature and humidity.

(7) With the compressor clutch engaged, record the discharge air temperature and the compressor discharge pressure.

(8) Compare the discharge air temperature to the Performance Temperature and Pressure chart. If the discharge air temperature is high, (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - DIAGNOSIS AND TESTING - REFRIGERANT SYSTEM LEAKS) and (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - SPECIFICATIONS - CHARGE CAPACITY).

Performance Temperature and Pressure

	Ambient Air	21° C	27° C	32° C	38° C	43° C
	Temperature	(70° F)	(80° F)	(90° F)	(100° F)	(110° F)
	Air Temperature at	7° C	7° C	13° C	13° C	18° C
	Center Panel Outlet	(45° F)	(45° F)	(55° F)	(55° F)	(64° F)
	Compressor Inlet	138 to 207 kPa	172 to 241	207 to 276	241 to 310	276 to 345 kPa
	Pressure at Service		kPa	kPa	kPa
		(20 to 30 psi)				(40 to 50 psi)
	Port (low Side)		(25 to 35 psi)	(30 to 40 psi)	(35 to 45 psi)
	Condensor Out	1034 to 1724	1379 to 2068	1724 to 2413	1999 to 2689	2413 to 2965
		kPa	kPa	kPa	kPa
	Pressuree at Service					kPa
		(150 to 250	(200 to 300	(250 to 350	(290 to 390
	Port (High Side)					(350 to 430 psi)
		psi)	psi)	psi)	psi)

(9) Compare the compressor discharge pressure to the Performance Temperature and Pressure chart. If

the compressor discharge pressure is high, see the Pressure Diagnosis chart.

Pressure Diagnosis

	Condition	Possible Causes	Correction
	Constant compressor		1. See Plumbing/Diagnosis and Testing -
		1. Low refrigerant system	Refrigerant System Leaks in this group. Test the
	engagement and warm air
		charge.	refrigerant system for leaks. Repair, evacuate and
	from passenger vents.
			charge the refrigerant system, if required.
	Equal pressures, but the	1. No refrigerant in the	1. See Plumbing/Diagnosis and Testing -
	compressor clutch does not	refrigerant system.	Refrigerant System Leaks in this group. Test the
	engage.		refrigerant system for leaks. Repair, evacuate and
			charge the refrigerant system, if required.
		2. Faulty fuse.	2. Check the fuses in the Power Distribution
			Center and the junction block. Repair the shorted
			circuit or component and replace the fuses, if
			required.
		3. Faulty a/c compressor	3. See A/C Compressor/Diagnosis and Testing -
		clutch coil.	Compressor Clutch Coil in this group. Test the
			compressor clutch coil and replace, if required.

24 - 4	HEATING & AIR CONDITIONING						DR
HEATING & AIR CONDITIONING (Continued)
				Pressure Diagnosis
	Condition		Possible Causes			Correction
		4.	Faulty a/c compressor		4.	See A/C Compressor Clutch Relay/Diagnosis
		clutch relay.			and Testing - Compressor Clutch Relay in this
					group. Test the compressor clutch relay and relay
					circuits. Repair the circuits or replace the relay, if
					required.
		5.	Improperly installed or		5.	See Fin Sensor/Diagnosis and Testing in this
		faulty Fin Sensor.			group. Reinstall or replace the Fin Sensor as
					required.
		6.	Faulty a/c high pressure		6.	See A/C High Pressure Transducer/Diagnosis
		transducer.			and Testing in this group. Test the a/c high
					pressure transducer and replace, if required.
		7.	Faulty Powertrain Control		7.	(Refer to Appropriate Diagnostic Information).
		Module (PCM).			Test the PCM and replace, if required.
Normal pressures, but A/C		1. Excessive refrigerant oil in			1.	See Refrigerant Oil/Standard Procedure -
Performance Test air		system.			Refrigerant Oil Level in this group. Recover the
temperatures at center panel					refrigerant from the refrigerant system and
outlet are too high.					inspect the refrigerant oil content. Restore the
					refrigerant oil to the proper level, if required.
		2.	Blend door inoperative or		2.	See Blend Door in this group. Inspect the
		sealing improperly.			blend door for proper operation and sealing and
					correct, if required.
		3.	Blend door actuator faulty		3.	Perform blend door actuator diagnosis, replace
		or inoperative.			if faulty.
The low side pressure is		1. Low refrigerant system			1.	See Plumbing/Diagnosis and Testing -
normal or slightly low, and		charge.			Refrigerant System Leaks in this group. Test the
the high side pressure is too					refrigerant system for leaks. Repair, evacuate and
low.					charge the refrigerant system, if required.
		2.	Refrigerant flow through		2.	See Accumulator in this group. Replace the
		the accumulator is restricted.			restricted accumulator, if required.
		3.	Refrigerant flow through		3.	See A/C Evaporator in this group. Replace the
		the evaporator coil is			restricted evaporator coil, if required.
		restricted.
		4.	Faulty compressor.		4.	See A/C Compressor in this group. Replace
					the compressor, if required.
The low side pressure is		1. Condenser air flow			1.	Check the condenser for damaged fins, foreign
normal or slightly high, and		restricted.			objects obstructing air flow through the condenser
the high side pressure is too					fins, and missing or improperly installed air seals.
high.					Refer to Cooling for more information on air
					seals. Clean, repair, or replace components as
					required.
		2.	Inoperative cooling fan.		2.	Refer to Cooling for more information. Test the
					cooling fan and replace, if required.
		3.	Refrigerant system		3.	See Plumbing/Standard Procedure -
		overcharged.			Refrigerant System Charge in this group. Recover
					the refrigerant from the refrigerant system.
					Charge the refrigerant system to the proper level,
					if required.

DR						HEATING & AIR CONDITIONING	24 - 5
HEATING & AIR CONDITIONING (Continued)
			Pressure Diagnosis
	Condition		Possible Causes			Correction
		4.	Air in the refrigerant	4.		See Plumbing/Diagnosis and Testing -
		system.		Refrigerant System Leaks in this group. Test the
				refrigerant system for leaks. Repair, evacuate and
				charge the refrigerant system, if required.
		5.	Engine overheating.	5.		Refer to Cooling for more information. Test the
				cooling system and repair, if required.
The low side pressure is too		1.	Accessory drive belt	1.		Refer to Cooling for more information. Inspect
high, and the high side		slipping.		the accessory drive belt condition and tension.
pressure is too low.				Tighten or replace the accessory drive belt, if
				required.
		2.	Fixed orifice tube not	2.		See A/C Orifice Tube in this group. Replace
		installed.		the liquid line, if required.
		3.	Faulty compressor.	3.		See A/C Compressor in this group. Replace
				the compressor, if required.
The low side pressure is too		1.	Restricted refrigerant flow	1.		See Liquid, Suction, and Discharge Line in this
low, and the high side		through the refrigerant lines.		group. Inspect the refrigerant lines for kinks, tight
pressure is too high.				bends or improper routing. Correct the routing or
				replace the refrigerant line, if required.
		2.	Restricted refrigerant flow	2.		See A/C Orifice Tube in this group. Replace
		through the fixed orifice tube.		the liquid line, if required.
		3.	Restricted refrigerant flow	3.		See A/C Condenser in this group. Replace the
		through the condenser.		restricted condenser, if required.

DIAGNOSIS AND TESTING - HEATER PERFORMANCE

Before performing the following tests, refer to Cooling for the procedures to check the engine coolant level and flow, engine coolant reserve/recovery system operation, accessory drive belt condition and tension, radiator air flow and the fan drive operation. Also be certain that the accessory vacuum supply line is connected at the engine vacuum source.

MAXIMUM HEATER OUTPUT

Engine coolant is delivered to the heater core through two heater hoses. With the engine idling at normal operating temperature, set the temperature control knob in the full hot position, the mode control switch knob in the floor position, and the blower motor switch knob in the highest speed position. Using a test thermometer, check the temperature of the air being discharged at the HVAC housing floor outlets. Compare the test thermometer reading to the Temperature Reference chart.

Temperature Reference

	Ambient Air Temperature	15.5° C	21.1° C	26.6° C	32.2° C
		(60° F)	(70° F)	(80° F)	(90° F)
	Minimum Air Temperature at	62.2° C	63.8° C	65.5° C	67.2° C
	Floor Outlet	(144° F)	(147° F)	(150° F)	(153° F)

24 - 6 HEATING & AIR CONDITIONING		DR

HEATING & AIR CONDITIONING (Continued)

If the floor outlet air temperature is too low, refer to Cooling to check the engine coolant temperature specifications. Both of the heater hoses should be hot to the touch. The coolant return heater hose should be slightly cooler than the coolant supply heater hose. If the return hose is much cooler than the supply hose, locate and repair the engine coolant flow obstruction in the cooling system. Refer to Cooling for the procedures.

An alternate method of checking heater performance is to use a DRBIIIt scan tool to monitor the engine coolant temperature. The floor outlet air temperature reading should be no more than 4.5° C (40° F) lower than the engine coolant temperature reading.

OBSTRUCTED COOLANT FLOW Possible locations or causes of obstructed coolant flow:

² Faulty water pump.

² Faulty thermostat.

² Pinched or kinked heater hoses.

² Improper heater hose routing.

² Plugged heater hoses or supply and return ports at the cooling system connections.

² A plugged heater core.

If proper coolant flow through the cooling system is verified, and heater outlet air temperature is still low, a mechanical problem may exist.

MECHANICAL PROBLEMS Possible locations or causes of insufficient heat:

² An obstructed cowl air intake.

² Obstructed heater system outlets.

² A faulty, obstructed or improperly installed blend door.

² A faulty blower system.

² A faulty a/c heater control.

TEMPERATURE CONTROL

If the heater outlet air temperature cannot be adjusted with the temperature control knob on the a/c heater control panel, the following could require service:

² A faulty a/c heater control.

² A faulty blend door actuator.

² A faulty, obstructed or improperly installed blend door.

² An obstructed cowl air intake.

² The engine cooling system.

Heater Diagnosis

CONDITION		POSSIBLE CAUSE		CORRECTION
INSUFFICIENT HEATER	1. Incorrect engine		1.	Check the engine coolant level. Refer to Cooling for
OUTPUT.	coolant level.		the procedures.
	2. Air trapped in engine		2.	Check the operation of the coolant reserve/recovery
	cooling system.		system. Refer to Cooling for the procedures.
	3.	Incorrect engine	3.	Check the performance and operation of the engine
	coolant temperature.		cooling system including: thermostat, water pump, fan
			drive, accessory drive belt, coolant flow (plugged radiator
			or heater core, plugged or kinked coolant hoses), air flow
			(missing or improperly installed radiator air seals or fan
			shroud). Refer to Cooling for the procedures.
	4.	Blend door actuator	4.	(Refer to Controls/Blend Door Actuator) in this group.
	inoperative or defective.
	5.	Blend door not	5.	Check for a damaged, obstructed or improperly
	operating properly.		installed blend door or seals. (Refer to Controls/Blend
			Door Actuator) in this group.
	6.	Insufficient air flow	6.	Remove foreign material or obstructions from cowl air
	through heater housing.		intake.
	7.	Improper blower motor	7.	(Refer to Distribution/Blower Motor/ Diagnosis and
	operation.		Testing) in this group.

DR		HEATING & AIR CONDITIONING 24 - 7

HEATING & AIR CONDITIONING (Continued)

STANDARD PROCEDURE - DIODE

REPLACEMENT

(1) Disconnect the battery negative cable and isolate it. If vehicle has a dual batterys remove both negative cables.

(2) Locate the diode in the harness, and remove the protective covering.

(3) Remove the diode from the harness, pay attention to the current flow direction (Fig. 2).

Fig. 2 DIODE IDENTIFICATION

1 - CURRENT FLOW

2 - BAND AROUND DIODE INDICATES CURRENT FLOW

3 - DIODE AS SHOWN IN THE DIAGRAMS

(4) Remove the insulation from the wires in the harness. Only remove enough insulation to solder in the new diode.

(5) Install the new diode in the harness, making sure current flow is correct. If necessary refer to the appropriate wiring diagram for current flow.

(6) Solder the connections together using rosin core type solder only. Do not use acid core solder.

(7) Tape the diode to the harness using electrical tape making, sure the diode is completely sealed from the elements.

(8) Re-connect the battery negative cable(s), and test affected systems.

SPECIFICATIONS

A/C APPLICATION TABLE

Item	Description	Notes
Vehicle	DRRam Truck
System	R134a w/ fixed
	orifice tube
Compressor	Saden SD-7	SP-15 PAG oil
Freeze±up	A/C Fin Sensor	Evaporator
Control		mounted
High psi Control	475 psi A/C cut	discharge line
	out
Control Head	electronic	Software -
		J2190
Mode Door	electric
Blend Door	electric
Recirculation	electric
Door
Blower Motor	hardwired to	resistor block
	control head
Cooling Fan	Viscous for
	cooling with a
	single speed
	electric for A/C
	for 3.7, 4.7 and
	5.7L gas
	engines.
	Viscous for
	both cooling
	and A/C with
	5.9L diesel
	engine and
	8.0L gas
	engine.
Clutch	Electro-
	mechanical
Control	relay	PCM
Draw	2 - 3.7 amps @	± 0.5V @ 70° F
	12V
Gap	0.0169 - 0.0319
DRB IIIT
Reads	TPS, RPM, A/C
	switch test
Actuators	clutch and fan
	relay

24 - 8 HEATING & AIR CONDITIONING		DR

HEATING & AIR CONDITIONING (Continued)

SPECIFICATIONS

TORQUE SPECIFICATIONS

	DESCRIPTION	N´m	Ft. Lbs.	In. Lbs.
	A/C COMPRESSOR	14.4	10.5	127.4
	CLUTCH PLATE NUT
	A/C COMPRESOR LINE	28 (±6)	21 (±4)	250 (±50)
	MANIFOLD FASTENER
	A/C COMPRESSOR TO	27	20	239
	MOUNTING BRACKET
	BOLTS
	ACCUMULATOR	5	3.7	44
	RETAINING BOLT
	BLEND DOOR ACTUATOR	2.4 (±.34)	1.8 (±.25)	21 (±3)
	SCREWS
	HVAC HOUSING SCREWS	2.4 (±.34)	1.8 (±.25)	21 (±3)
	HVAC HOUSING TO DASH	6.2	4.6	55
	PANEL NUTS
	SUCTION LINE TO	9	6.6	80
	ACCUMULATOR FITTING

CONTROLS

TABLE OF CONTENTS

	page
A/C COMPRESSOR CLUTCH
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . .	. . . 9
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . .	. . 9
DIAGNOSIS AND TESTING - A/C
COMPRESSOR CLUTCH COIL . . . . . . . . . .	. 10
STANDARD PROCEDURE - A/C
COMPRESSOR CLUTCH BREAK-IN . . . . . .	. 10
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 10
INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . .	. 12
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . .	. 12
A/C COMPRESSOR CLUTCH RELAY
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . .	. 13
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . .	. 13
DIAGNOSIS AND TESTING - COMPRESSOR
CLUTCH RELAY . . . . . . . . . . . . . . . . . . . . .	. 13
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 14
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . .	. 14
A/C HEATER CONTROL
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . .	. 14
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 14
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . .	. 15
A/C PRESSURE TRANSDUCER
DESCRIPTION - A/C PRESSURE
TRANSDUCER . . . . . . . . . . . . . . . . . . . . . .	. 15
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . .	. 15
DIAGNOSIS AND TESTING - A/C PRESSURE
TRANSDUCER . . . . . . . . . . . . . . . . . . . . . .	. 15
REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 16
INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . .	. 16
BLEND DOOR ACTUATOR
DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . .	. 16
OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . .	. 16

page

REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 17

BLOWER MOTOR RESISTOR BLOCK

DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 17 OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 DIAGNOSIS AND TESTING - BLOWER

MOTOR RESISTOR . . . . . . . . . . . . . . . . . . . . 18 REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 18

BLOWER MOTOR SWITCH

DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 18 OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 DIAGNOSIS AND TESTING - BLOWER

MOTOR SWITCH . . . . . . . . . . . . . . . . . . . . . . 18 REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 19

DEFROST DOOR ACTUATOR

REMOVAL - FLOOR - DEFROST DOOR

ACTUATOR . . . . . . . . . . . . . . . . . . . . . . . . . . 19 INSTALLATION - FLOOR - DEFROST DOOR

ACTUATOR . . . . . . . . . . . . . . . . . . . . . . . . . . 20

MODE DOOR ACTUATOR

DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 20 OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 22

RECIRCULATION DOOR ACTUATOR

DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . 22 OPERATION . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 REMOVAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 INSTALLATION . . . . . . . . . . . . . . . . . . . . . . . . . 23

A/C COMPRESSOR CLUTCH

DESCRIPTION

The compressor clutch assembly consists of a stationary electromagnetic coil, a rotor bearing and rotor assembly, and a clutch plate (Fig. 1). The electromagnetic coil unit and the rotor bearing and rotor assembly are each retained on the nose of the compressor front housing with snap rings. The clutch plate is keyed to the compressor shaft and secured with a nut. These components provide the means to engage and disengage the compressor from the engine serpentine accessory drive belt.

OPERATION

When the clutch coil is energized, it magnetically draws the clutch into contact with the rotor and drives the compressor shaft. When the coil is not energized, the rotor freewheels on the clutch rotor bearing, which is part of the rotor. The compressor clutch and coil are the only serviced parts on the compressor.

The compressor clutch engagement is controlled by several components: the A/C Heater mode control switch, the A/C high pressure transducer, the compressor clutch relay, and the (JTEC). The JTEC may delay compressor clutch engagement for up to thirty

24 - 10 CONTROLS

A/C COMPRESSOR CLUTCH (Continued)

Fig. 1 COMPRESSOR CLUTCH - TYPICAL

1 - CLUTCH PLATE

2 - SHAFT KEY (not used on KJ)

3 - ROTOR

4 - COIL

5 - CLUTCH SHIMS

6 - SNAP RING

7 - SNAP RING

seconds. Refer to Electronic Control Modules for more information on the JTEC controls.

DIAGNOSIS AND TESTING - A/C COMPRESSOR CLUTCH COIL

For circuit descriptions and diagrams, (Refer to Appropriate Wiring Information). The battery must be fully-charged before performing the following tests. Refer to Battery for more information.

(1) Connect an ammeter (0 to 10 ampere scale) in series with the clutch coil terminal. Use a voltmeter (0 to 20 volt scale) with clip-type leads for measuring the voltage across the battery and the compressor clutch coil.

(2) With the A/C Heater mode control switch in any A/C mode, and the blower motor switch in the lowest speed position, start the engine and run it at normal idle.

(3) The compressor clutch coil voltage should read within 0.2 volts of the battery voltage. If there is voltage at the clutch coil, but the reading is not within 0.2 volts of the battery voltage, test the clutch coil feed circuit for excessive voltage drop and repair as required. If there is no voltage reading at the clutch coil, use a DRB III t scan tool and (Refer to Appropriate Diagnostic Information) for testing of the compressor clutch circuit and PCM control. The following components must be checked and repaired as required before you can complete testing of the clutch

coil:

² Fuses in the junction block and the Power Dis-

tribution Center (PDC)

² A/C heater mode control switch ² Compressor clutch relay

² A/C high pressure transducer switch

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² JTEC

(4) The compressor clutch coil is acceptable if the current draw measured at the clutch coil is 2.0 to 3.9 amperes with the electrical system voltage at 11.5 to 12.5 volts. This should only be checked with the work area temperature at 21° C (70° F). If system voltage is more than 12.5 volts, add electrical loads by turning on electrical accessories until the system voltage drops below 12.5 volts.

(a) If the clutch coil current reading is four amperes or more, the coil is shorted and should be replaced.

(b) If the clutch coil current reading is zero, the coil is open and should be replaced.

STANDARD PROCEDURE - A/C COMPRESSOR CLUTCH BREAK-IN

After a new compressor clutch has been installed, cycle the compressor clutch approximately twenty times (five seconds on, then five seconds off). During this procedure, set the A/C Heater control to the Recirculation Mode, the blower motor switch in the highest speed position, and the engine speed at 1500 to 2000 rpm. This procedure (burnishing) will seat the opposing friction surfaces and provide a higher compressor clutch torque capability.

REMOVAL

The refrigerant system can remain fully-charged during compressor clutch, rotor, or coil replacement. The compressor clutch can be serviced in the vehicle.

(1) Disconnect and isolate the battery negative

cable.

(2) Remove the serpentine drive belt(Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE BELTS - REMOVAL).

(3) Unplug the compressor clutch coil wire harness connector.

(4) Remove the bolts that secure the compressor to the mounting bracket.

(5) Remove the compressor from the mounting bracket. Support the compressor in the engine compartment while servicing the clutch.

(6) Insert the two pins of the spanner wrench (Special Tool C-4489 or equivalent) into the holes of the clutch plate. Hold the clutch plate stationary and remove the hex nut (Fig. 2).

(7) Remove the clutch plate.

(8) Remove the compressor clutch shims.

(9) Remove the external front housing snap ring with snap ring pliers (Fig. 3).

(10) Install the lip of the rotor puller (Special Tool C-6141-1 or equivalent) into the snap ring groove exposed in the previous step, and install the shaft protector (Special Tool C-6141-2 or equivalent) (Fig. 4).

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A/C COMPRESSOR CLUTCH (Continued)

Fig. 2 CLUTCH NUT REMOVE - Typical

1 - CLUTCH PLATE

2 - SPANNER

Fig. 3 EXTERNAL SNAP RING REMOVE - Typical

1 - PULLEY

2 - SNAP RING PLIERS

Fig. 4 SHAFT PROTECTOR AND PULLER - Typical

1 - PULLER JAW

2 - SHAFT PROTECTOR

CONTROLS 24 - 11

(11) Install the puller through-bolts (Special Tool C-6461 or equivalent) through the puller flange and into the jaws of the rotor puller and tighten (Fig. 5). Turn the puller center bolt clockwise until the rotor is free.

CAUTION: DO NOT APPLY FORCE TO THE END OF THE COMPRESSOR SHAFT.

Fig. 5 INSTALL PULLER PLATE - Typical

1 - PULLER JAW

2 - PULLER

(12) Remove the screw and retainer from the clutch coil lead wire harness on the compressor front housing (Fig. 6).

Fig. 6 CLUTCH COIL LEAD WIRE HARNESS -

Typical

1 - COIL

2 - COIL WIRE

3 - RETAINER SCREW

(13) Remove the snap ring from the compressor hub and remove the clutch field coil (Fig. 7). Slide the clutch field coil off of the compressor hub.

A/C COMPRESSOR CLUTCH (Continued)

Fig. 7 CLUTCH FIELD COIL SNAP RING REMOVE -

Typical

1 - COIL

2 - SNAP RING PLIERS

INSPECTION

Examine the friction surfaces of the clutch rotor and the clutch plate for wear. The rotor and clutch plate should be replaced if there is excessive wear or scoring.

If the friction surfaces are oily, inspect the shaft and nose area of the compressor for oil. Remove the felt from the front cover. If the felt is saturated with oil, the shaft seal is leaking and the compressor must be replaced.

Check the rotor bearing for roughness or excessive leakage of grease. Replace the rotor and clutch plate, if required.

Fig. 8 CLUTCH PULLEY INSTALL - Typical

1 - ROTOR BEARING ASSEMBLY

2 - INSTALLER

(6) Install the original clutch shims on the compressor shaft.

(7) Install the clutch plate. Install the shaft hex nut and tighten to 15±20 N´m (11±15 ft. lbs.).

(8) Check the clutch air gap with a feeler gauge (Fig. 9). If the air gap does not meet the specification, add or subtract shims as required. The air gap specification is 0.41 to 0.79 millimeter (0.016 to 0.031 inch).

INSTALLATION

(1) Install the clutch field coil and snap ring.

(2) Install the screw and retainer on the clutch coil lead wire harness on the compressor front housing. Tighten screw to 2.2 N´m (20 in. lbs.).

(3) Align the rotor assembly squarely on the front compressor housing hub.

(4) Install the rotor bearing assembly with the installer (Special Tool C-6871 or equivalent) (Fig. 8). Thread the installer on the shaft, then turn the nut until the rotor assembly is seated.

(5) Install the external front housing snap ring with snap ring pliers. The bevel side of the snap ring must be facing outward. Press the snap ring to make sure it is properly seated in the groove.

CAUTION: If the snap ring is not fully seated in the groove it will vibrate out, resulting in a clutch failure and severe damage to the front housing of the compressor.

Fig. 9 CHECK CLUTCH AIR GAP - Typical

1 - FEELER GAUGE

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A/C COMPRESSOR CLUTCH (Continued)

NOTE: The air gap is determined by the spacer shims. When installing an original, or a new clutch assembly, try the original shims first. When installing a new clutch onto a compressor that previously did not have a clutch, use a 1.0, 0.50, and 0.13 millimeter (0.040, 0.020, and 0.005 inch) shims from the new clutch hardware package that is provided with the new clutch.

(9) To complete the procedure, (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING/A/C COMPRESSOR - INSTALLATION).

A/C COMPRESSOR CLUTCH RELAY

DESCRIPTION

The compressor clutch relay is a International Standards Organization (ISO) micro-relay. The terminal designations and functions are the same as a conventional ISO relay. However, the micro-relay terminal orientation (footprint) is different, the current capacity is lower, and the relay case dimensions are smaller than those of the conventional ISO relay.

The compressor clutch relay is located in the Power Distribution Center (PDC) in the engine compartment. Refer to the PDC label for relay identification and location.

OPERATION

The compressor clutch relay is a electromechanical device that switches battery current to the compressor clutch coil when the Powertrain Control Module (PCM) grounds the coil side of the relay. The PCM responds to inputs from the A/C Heater mode control switch, the A/C low pressure switch, and the A/C high pressure switch. (Refer to 24 - HEATING & AIR CONDITIONING/CONTROLS/A/C COMPRESSOR CLUTCH RELAY - DIAGNOSIS AND TESTING)

The compressor clutch relay cannot be repaired and, if faulty or damaged, it must be replaced.

DIAGNOSIS AND TESTING - COMPRESSOR CLUTCH RELAY

RELAY TEST

The compressor clutch relay (Fig. 10) is located in the Power Distribution Center (PDC). Refer to the PDC label for relay identification and location. Remove the relay from the PDC to perform the following tests:

(1) A relay in the de-energized position should have continuity between terminals 87A and 30, and no continuity between terminals 87 and 30. If OK, go to Step 2. If not OK, replace the faulty relay.

CONTROLS 24 - 13

(2) Resistance between terminals 85 and 86 (electromagnet) should be 67.5 to 82.5 ohms. If OK, go to Step 3. If not OK, replace the faulty relay.

(3) Connect a battery to terminals 85 and 86. There should now be continuity between terminals 30 and 87, and no continuity between terminals 87A and 30. If OK, see Relay Circuit Test. If not OK, replace the faulty relay.

Fig. 10 COMPRESSOR CLUTCH RELAY

30 - COMMON FEED

85 - COIL GROUND

86 - COIL BATTERY

87 - NORMALLY OPEN

87A - NORMALLY CLOSED

RELAY CIRCUIT TEST

For circuit descriptions and diagrams, (Refer to Appropriate Wiring Information).

(1) The relay common feed terminal cavity (30) is connected to fused battery feed. There should be battery voltage at the cavity for relay terminal 30 at all times. If OK, go to Step 2. If not OK, repair the open circuit to the fuse in the PDC as required.

(2) The relay normally closed terminal (87A) is not used in this application. Go to Step 3.

(3) The relay normally open terminal cavity (87) is connected to the compressor clutch coil. There should be continuity between this cavity and the A/C compressor clutch relay output circuit cavity of the compressor clutch coil wire harness connector. If OK, go to Step 4. If not OK, repair the open circuit as required.

(4) The relay coil battery terminal (86) is connected to the fused ignition switch output (run/start) circuit. There should be battery voltage at the cavity

A/C COMPRESSOR CLUTCH RELAY (Continued)

for relay terminal 86 with the ignition switch in the On position. If OK, go to Step 5. If not OK, repair the open circuit to the fuse in the junction block as required.

(5) The coil ground terminal cavity (85) is switched to ground through the Powertrain Control Module (PCM). There should be continuity between this cavity and the A/C compressor clutch relay control circuit cavity of the PCM wire harness connector C (gray) at all times. If not OK, repair the open circuit as required.

REMOVAL

(1) Disconnect and isolate the battery negative

cable.

(2) Remove the cover from the Power Distribution Center (PDC).

(3) Refer to the label on the PDC for compressor clutch relay identification and location.

(4) Unplug the compressor clutch relay from the

PDC.

INSTALLATION

(1) Install the compressor clutch relay by aligning the relay terminals with the cavities in the PDC and pushing the relay firmly into place.

(2) Install the PDC cover.

(3) Connect the battery negative cable.

(4) Test the relay operation.

A/C HEATER CONTROL

DESCRIPTION

The A/C heater system uses a seriers of electrical controls. These controls provide the vehicle operator with a number of setting options to help control the climate and comfort within the vehicle. Refer to the owner's manual in the vehicle glove box for more information on the features, use, and suggested operation of these controls.

The A/C heater control - (Single Zone) or (Dual Zone) panel is located to the right of the instrument cluster on the instrument panel.

The control panel contains a rotary-type temperature control, a rotary-type mode control switch knob, and a rotary-type blower motor speed switch knob. The control also has a push button to activate the Optional side view mirrors defroster elements and to turn the A/C on.

The Dual Zone HVAC control panel contains a pair of slider-type temperature controls, a rotary-type mode control switch knob and a rotary-type blower motor speed switch knob. The control also has buttons to turn the A/C ON, Set it on Max A/C and for the Optional Heated Sideview Mirrors.

The A/C heater control panel cannot be repaired. If faulty or damaged, the entire unit must be replaced. The illumination lamps are available for service replacement.

REMOVAL

WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN AN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

(1) Disconnect and isolate the battery negative

cable.

(2) Remove the center bezel from the instrument panel(Refer to 23 - BODY/INSTRUMENT PANEL/INSTRUMENT PANEL CENTER BEZEL - REMOVAL).

(3) Remove the screws that secure the A/C Heater control to the instrument panel (Fig. 11) or (Fig. 12).

(4) Pull the A/C Heater control assembly away from the instrument panel far enough to access the connections on the back of the control.

Fig. 11 Single Zone HVAC Control

1 - Mounting Tab (4)

2 - A/C Button

3 - Sideview Mirror Defroster Button (if equiped)

4 - Mode Control

5 - Blend Air Control

6 - Blower Motor Speed Control

(5) Unplug the wire harness connectors from the back of the A/C Heater control (Fig. 13).

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A/C HEATER CONTROL (Continued)

Fig. 12 Dual Zone A/C Control

1 - A/C Button

2 - Max. A/C Button

3 - Sideview Mirror Defrost Button (if equiped)

4 - Mounting Tabs (4)

5 - Driverside Temperature Control

6 - Passengerside Temperature Control

7 - Mode Control

8 - Blower Motor Speed Control

Fig. 13 HVAC Control - (Rear Viewtypical)

1 - Mounting Tabs (4)

2 - Mounting Screws (4)

3 - HVAC Control Connector

4 - Heated Sideview Mirror Connector

5 - HVAC Control Assembly

INSTALLATION

(1) Plug the two wire harness connectors into the back of the A/C Heater control.

(2) Position the A/C Heater control in the instrument panel bezel and secure it with four screws. Tighten the screws to 2.2 N´m (20 in. lbs.).

(3) Reinstall the center bezel onto the instrument panel(Refer to 23 - BODY/INSTRUMENT PANEL/INSTRUMENT PANEL CENTER BEZEL - INSTALLATION).

(4) Connect the battery negative cable.

CONTROLS 24 - 15

A/C PRESSURE TRANSDUCER

DESCRIPTION - A/C PRESSURE TRANSDUCER

The A/C pressure transducer is a switch that is installed on a fitting located on the refrigerant discharge line between the compressor and the condensor in the front corner of the engine compartment. An internally threaded hex fitting on the transducer connects it to the externally threaded Schrader-type fitting on the liquid line. A rubber O-ring seals the connection between the transducer and the discharge line fitting. Three terminals within a molded plastic connector receptacle on the top of the transducer connect it to the vehicle electrical system through a take out and connector of the headlamp and dash wire harness.

The A/C pressure transducer cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.

OPERATION

The A/C pressure transducer monitors the pressures in the high side of the refrigerant system through its connection to a fitting on the discharge line. The transducer will change its internal resistance in response to the pressures it monitors. The Powertrain Control Module (PCM) provides a five volt reference signal and a sensor ground to the transducer, then monitors the output voltage of the transducer on a sensor return circuit to determine refrigerant pressure. The PCM is programmed to respond to this and other sensor inputs by controlling the operation of the air conditioning compressor clutch and the radiator cooling fan to help optimize air conditioning system performance and to protect the system components from damage. The A/C pressure transducer input to the PCM will also prevent the air conditioning compressor clutch from engaging when ambient temperatures are below about 10° C due to the pressure/temperature relationship of the refrigerant. The Schrader-type valve in the discharge line fitting permits the A/C pressure transducer to be removed or installed without disturbing the refrigerant in the system. The A/C pressure transducer is diagnosed using a DRBIIIt scan tool. Refer to the appropriate diagnostic information.

DIAGNOSIS AND TESTING - A/C PRESSURE TRANSDUCER

The A/C pressure transducer is tested using a DRBIIIt scan tool. Refer to the appropriate diagnostic information. Before testing the A/C pressure transducer, be certain that the transducer wire harness connection is clean of corrosion and properly connected. For the air conditioning system to operate,

24 - 16 CONTROLS

A/C PRESSURE TRANSDUCER (Continued)

an A/C pressure transducer voltage reading between 0.451 and 4.519 volts is required. Voltages outside this range indicate a low or high refrigerant system pressure condition to the Powertrain Control Module (PCM). The PCM is programmed to respond to a low or high refrigerant system pressure by suppressing operation of the compressor. Refer to the A/C Pressure Transducer Voltage table for the possible condition indicated by the transducer voltage readings.

A/C PRESSURE TRANSDUCER VOLTAGE

VOLTAGE		POSSIBLE INDICATION
0.0	1.	NO SENSOR SUPPLY
	VOLTAGE FROM PCM.
	2.	SHORTED SENSOR CIRCUIT.
	3.	FAULTY TRANSDUCER.
0.150 TO 0.450	1. AMBIENT TEMPERATURE
	BELOW 10° C (50° F).
	2.	LOW REFRIGERANT
	SYSTEM PRESSURE.
0.451 TO 4.519	1. NORMAL REFRIGERANT
	SYSTEM PRESSURE.
4.520 TO 4.850	1. HIGH REFRIGERANT
	SYSTEM PRESSURE.
5.0	1.	OPEN SENSOR CIRCUIT.
	2.	FAULTY TRANSDUCER.

REMOVAL

(1) Disconnect and isolate the battery negative

cable.

(2) Disconnect the wire harness connector for the A/C pressure transducer from the transducer connector receptacle.

(3) Using an open end wrench, unscrew the A/C pressure transducer from the fitting on the discharge line between the compressor and the condenser.

(4) Remove the seal from the A/C pressure transducer fitting and discard.

INSTALLATION

(1) Lubricate a new rubber O-ring seal with clean refrigerant oil and install it on the A/C pressure transducer fitting.

(2) Using an open end wrench, install and tighten the A/C pressure transducer onto the fitting on the discharge line between the compressor and the condenser.

(3) Reconnect the wire harness connector for the A/C pressure transducer to the transducer connector receptacle.

(4) Reconnect the battery negative cable.

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BLEND DOOR ACTUATOR

DESCRIPTION

The blend door actuators are reversible, 12-volt Direct Current (DC), servo motors. Models with the single zone heater and air conditioner system have a single blend air door, which is controlled by a single blend door actuator. Models with the optional dual zone front heater and air conditioner system have dual blend air doors, which are controlled by two blend door actuators. The single zone blend door actuator is located on the driver side end of the heat- er-A/C housing unit, close to the dash panel. In the dual zone system, the same blend door actuator used for the single zone system becomes the driver side blend door actuator, and is mechanically connected to only the driver side blend air door. In the dual zone system, a second separate blend door actuator is also located on the top of the heater-A/C housing unit and is mechanically connected to only the passenger side blend air door.

The blend door actuators are interchangeable with each other, as well as with the actuators for the mode door and the recirculation air door. Each actuator is contained within an identical black molded plastic housing with an integral wire connector receptacle. Two integral mounting tabs allow the actuator to be secured with two screws to the heater- A/C unit housing. Each actuator also has an identical output shaft with splines that connects it to the linkage that drives the proper blend air door. The blend door actuators do not require mechanical indexing to the blend door linkage, as they are electronically calibrated by the heater-A/C control module. The blend door actuators cannot be adjusted or repaired and, if damaged or faulty, they must be replaced.

OPERATION

Each blend door actuator is connected to the heat- er-A/C control module through the vehicle electrical system by a dedicated two-wire take out and connector of the HVAC wire harness. The blend door actuator can move the blend air door in two directions. When the heater-A/C control module pulls the voltage on one side of the motor connection high and the other connection low, the blend air door will move in one direction. When the module reverses the polarity of the voltage to the motor, the blend air door moves in the opposite direction. When the module makes the voltage to both connections high or both connections low, the blend air door stops and will not move. These same motor connections also provide a feedback signal to the heater-A/C control module. This feedback signal allows the module to monitor the operation and relative positions of the blend door actuator and the blend air door. The heater-A/C con-

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BLEND DOOR ACTUATOR (Continued)

trol module learns the blend air door stop positions during the calibration procedure and will store a Diagnostic Trouble Code (DTC) for any problems it detects in the blend door actuator circuits. The blend door actuator can be diagnosed using a DRBIIIt scan tool. Refer to the appropriate diagnostic information.

REMOVAL

The single zone heating and air conditioning system is equipped with a single blend door actuator. The dual zone system has two blend door actuators, one for the driver side blend air door and one for the passenger side blend air door. The same service procedures can be used for each of these actuators.

WARNING: ON VEHICLES EQUIPPED WITH AIRBAGS, DISABLE THE AIRBAG SYSTEM BEFORE ATTEMPTING ANY STEERING WHEEL, STEERING COLUMN, OR INSTRUMENT PANEL COMPONENT DIAGNOSIS OR SERVICE. DISCONNECT AND ISOLATE THE BATTERY NEGATIVE (GROUND) CABLE, THEN WAIT TWO MINUTES FOR THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE BEFORE PERFORMING FURTHER DIAGNOSIS OR SERVICE. THIS IS THE ONLY SURE WAY TO DISABLE THE AIRBAG SYSTEM. FAILURE TO TAKE THE PROPER PRECAUTIONS COULD RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL INJURY.

(1) Disconnect and isolate the battery negative

cable.

(2) Remove the instrument panel assembly(Refer to 23 - BODY/INSTRUMENT PANEL/INSTRUMENT PANEL ASSEMBLY - REMOVAL).

(3) Disconnect the HVAC wire harness connector for the blend door actuator from the actuator connector receptacle. (Fig. 14)

(4) Remove the screws that secure the blend door actuator to the distribution housing.

(5) Remove the blend door actuator from the distribution housing.

INSTALLATION

(1) Position the blend door actuator into the heater/air conditioner housing. If necessary, rotate the actuator slightly to align the splines on the actuator output shaft with those in the blend air door linkage.

(2) Install and tighten the three screws that secure the blend door actuator to the distribution housing. Tighten the screws to 2 N´m (17 in. lbs.).

(3) Reconnect the HVAC wire harness connector for the blend door actuator to the actuator connector receptacle.

(4) Install the instrument panel assembly(Refer to 23 - BODY/INSTRUMENT PANEL/INSTRUMENT PANEL ASSEMBLY - INSTALLATION).

CONTROLS 24 - 17

Fig. 14 HVAC Housing - Dual Zone Shown (Typical -

Single Zone)

1 - Mounting Nut

2 - Passenger Blend Door Actuator (dual zone)

3 - Mounting Nut

4 - Air Intake Spacer

5 - Recirculation Door Actuator

6 - Recirculation Door Assembly

7 - Driver Side Blend Door Actuator

8 - HVAC Housing

9 - Mounting Screw

10 - Defroster Door Actuator

11 - Panel Actuator

(5) Reconnect the battery negative cable.

(6) Perform the heater-A/C control calibration procedure. (Refer to 24 - HEATING & AIR CONDITIONING/CONTROLS - FRONT/A/C-HEATER CONTROL

- STANDARD PROCEDURE - HEATER-A/C CONTROL CALIBRATION).

BLOWER MOTOR RESISTOR BLOCK

DESCRIPTION

The blower motor resistor is mounted to the rear side of the HVAC housing on the passenger side of the vehicle.

OPERATION

The resistor is a ceramic resistor that utilizes resistor circuit tracers to reduce current flow to the

Where Is The Low Side Air Conditioning Service Port

Source: https://manualmachine.com/dodge/heatingairconditioning/4537193-factory-service-manual/

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