cooling DODGE RAM SRT-10 2006 Service Repair Manual

TRANSDUCER-A/C PRESSURE
DESCRIPTION
The A/C pressure transducer (1) is a switch that is
installed on a fitting located on the A/C discharge line.
An internally threaded fitting on the A/C pressure
transducer connects it to the externally threaded
Schrader-type fitting on the A/C discharge line. A rub-
ber O-ring seals the connection between the A/C pres-
sure transducer and the discharge line fitting. The A/C
pressure transducer is connected to the vehicle elec-
trical system by a molded plastic connector with three
terminals.
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 A/C discharge line. The A/C pressure transducer will change its internal resistance in response to
the pressures it monitors. A Schrader-type valve in the A/C discharge linefitting permits the A/C pressure transducer
to be removed or installed without disturbing the refrigerant in the A/C system.
The A/C pressure transducer will change its internal resistance in response to the pressures it monitors. The pow-
ertrain control module (PCM) or the engine control module (ECM) (depending on engine application) provides a five
volt reference signal and a sensor ground to the A/C pressure transducer, then monitors the output voltage of the
transducer on a sensor return circuit to determine refrigerant pressure.The PCM/ECM is programmed to respond to
this and other sensor inputs by controlling the operation of the A/C compressor clutch and the radiator cooling fan
to help optimize A/C system performance and to protect the system components from damage. The PCM will dis-
engagetheA/Ccompressorclutchwhenhighsidepressurerisesabove3172kPa (460 psi) and re-engage the
clutch when high side pressure drops below 1999 kPa (290 psi). The A/C pressure transducer will also disengage
the A/C compressor clutch if the high side pressure drops below 193 kPa (28 psi) and will re-engage the clutch
when the high side pressure rises above 234 kPa (34 psi). If the refrigerantpressure rises above 1655 kPa (240
psi), the PCM will actuate the cooling fan. The A/C pressure transducer signal to the PCM/ECM will also prevent the
A/C compressor clutch from engaging when ambient temperatures are below about 10° C (50° F) due to the pres-
sure/temperature relationship of the refrigerant. The A/C pressure transducer input to the PCM/ECM will also pre-
vent the A/C compressor clutch from engaging when ambient temperatures are below about 10° C (50° F) due to
the pressure/temperature relationship of the refrigerant.
The A/C pressure transducer is diagnosed using a scan tool. Refer to 9 - Engine Electrical Diagnostics for more
information.
The A/C pressure transducer cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.
REMOVAL
NOTE: It is not necessary to discharge the refrigerant system to replace the A/C pressure transducer.

REMOVAL
HVAC HOUSING ASSEMBLY
WARNING: Refer to the applicable warnings and cautions for this system before performing the following
operation (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - WARNINGS) and (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - CAUTIONS). Failure to follow the warnings and cautions could result
in possible personal injury or death.
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
negative battery (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 deploymentand possible personal injury or
death.
NOTE: The HVAC housing must be removedfrom the vehicle and disassembled for service of the A/C evap-
orator, evaporator temperature sensor, mode-air and blend-air doors.
1. Recover the refrigerant from the refrigerant system
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - STANDARD PROCEDURE -
REFRIGERANT SYSTEM RECOVERY).
2. Drain the engine cooling system (Refer to 7 -
COOLING - STANDARD PROCEDURE - COOL-
ING SYSTEM DRAIN).
3. Disconnect and isolate the negative battery cable.
4. Disconnect the A/C liquid line and the A/C accumu-
lator from the A/C evaporator (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING/LINE-A/C
LIQUID - REMOVAL) and (Refer to 24 - HEATING
& AIR CONDITIONING/PLUMBING/ACCUMULA-
TOR-A/C - REMOVAL).
5. Disconnect the heater hoses from the heater core
tubes.
6. Remove the powertrain control module (PCM) to
gain access to the two nuts (3) that secure the
HVAC housing (1) to the engine compartment side of the dash panel (2) and remove the nuts (Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MODULES/POWERTRAIN CONTROL MODULE - REMOVAL).

1. If removed, install the fresh air inlet (2) onto the
dash panel (1).
2. Position the HVAC housing assembly (4) into the
passenger compartment with the mounting studs
and the condensate drain tube in their proper loca-
tions in the dash panel.
3. Install the two nuts (3 and 7) that secure the HVAC
housing to the passenger compartment side of the
dash panel. Tighten the nuts to 6.2 Nꞏm (55 in.
lbs.).
4. Install the bolt (5) that secures the HVAC housing
to the floor bracket (6). Tighten the bolt to 6.2 Nꞏm
(55 in. lbs.).
5. Install the instrument panel (Refer to 23 - BODY/
INSTRUMENT PANEL ASSEMBLY - INSTALLA-
TION).
6. On Mega Cab models, install the floor console duct
(Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION/DUCT-FLOOR CONSOLE - INSTALLATION).
7. Install the two nuts (3) that secure the HVAC hous-
ing (1) to the engine compartment side of the dash
panel (2). Tighten the nuts to 6.2 Nꞏm (55 in. lbs.).
8. Install the powertrain control module (PCM) (Refer
to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/POWERTRAIN CONTROL MODULE -
INSTALLATION).
9. Connect the heater hoses to the heater core tubes.
10. Connect the A/C liquid line and the A/C accumu-
lator to the A/C evaporator (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING /LINE-
A/C LIQUID - INSTALLATION) and (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/AC-
CUMULATOR-A/C - INSTALLATION).
11. Reconnect the negative battery cable.
12. If the heater core is being replaced, flush the
coolingsystem(Referto7-COOLING-STAN-
DARD PROCEDURE - COOLING SYSTEM
CLEANING/REVERSE FLUSHING).
13. Refill the engine cooling system (Refer to 7 - COOLING - STANDARD PROCEDURE - COOLING SYSTEM
REFILL).
14. Evacuate the refrigerant system (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - STANDARD
PROCEDURE - REFRIGERANT SYSTEM EVACUATE).
15. Charge the refrigerant system (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - STANDARD PRO-
CEDURE - REFRIGERANT SYSTEM CHARGE).
AIR INLET HOUSING
NOTE: The air inlet housing must be removed from HVAC housing and disassembled for service of the
recirculation-air door.

WARNING: The engine cooling system is designed to develop internal pressures up to 145 kilopascals (21
pounds per square inch). Do not remove or loosen the coolant pressure cap, cylinder block drain plugs,
radiator drain, radiator hoses, heater hoses, or hose clamps while the engine cooling system is hot and
under pressure. Allow the vehicle to cool for a minimum of 15 minutes beforeopening the cooling system
for service. Failure to observe this warning can result in serious burns from the heated engine coolant.
CAUTION
CAUTION: Never add R-12 to a refrigerant system designed to use R-134a. Do not use R-12 equipment or
parts on an R-134a A/C system. These refrigerants are not compatible and damage to the A/C system will
result.
CAUTION: Never use R-12 refrigerant oil in a A/C system designed to use R-134a refrigerant oil. These
refrigerant oils are not compatible and damage to the A/C system will result.
CAUTION: The use of A/C system sealers may result in damage to A/C refrigerant recovery/evacuation/re-
charging equipment and/or A/C system. Many federal, state/provincial and local regulations prohibit the
recharge of A/C systems with known leaks. DaimlerChrysler recommends thedetection of A/C system leaks
through the use of approved leak detectors and fluorescent leak detectiondyes. Vehicles found with A/C
system sealers should be treated as contaminated and replacement of the entire A/C refrigerant system is
recommended. A/C systems found to be contaminated with A/C system sealers, A/C stop-leak products or
seal conditioners voids the warranty for the A/C system.
CAUTION: Recover the refrigerant before opening any fitting or connection. Open the fittings with caution,
even after the system has been discharged. Never open or loosen a connection before recovering the refrig-
erant.
CAUTION: If equipped, do not remove the secondary retention clip from any spring-lock coupler connection
while the refrigerant system is under pressure. Recover the refrigerant before removing the secondary
retention clip. Open the fittings with caution, even after the system has been discharged. Never open or
loosen a connection before recovering the refrigerant.
CAUTION: The internal parts of the A/C system will remain stable as long as moisture-free refrigerant and
refrigerant oil is used. Abnormal amounts of dirt, moisture or air can upset the chemical stability. This may
cause operational troubles or even serious damage if present in more than very small quantities. Before
disconnecting a component, clean the outside of the fittings thoroughly to prevent contamination from
entering the refrigerant system. Keep service tools and the work area clean. Do not open the refrigerant
system or uncap a replacement component until you are ready to service the system. Immediately after
disconnecting a component from the refrigerant system, seal the open fittings with a cap or plug. This will
prevent contamination from entering the A/C system.
CAUTION: Refrigerant oil will absorb moisture from the atmosphere if leftuncapped. Do not open a con-
tainer of refrigerant oil until you are ready to use it. Replace the cap on the oil container immediately after
using. Store refrigerant oil only in a clean, airtight, and moisture-freecontainer.
CAUTION: Do not overcharge the refrigerant system. Overcharging will cause excessive compressor head
pressure and can cause compressor noise and A/C system failure.

DIAGNOSIS AND TESTING
A/C COMPRESSOR
When investigating an A/C system related noise, you must first know the conditions under which the noise occurs.
These conditions include: weather, vehicle speed, transmission in gear or neutral, engine speed, engine tempera-
ture, and any other special conditions. Noises that develop during A/C operation can often be misleading. For exam-
ple: What sounds like a failed front engine bearing or connecting rod, may be caused by loose bolts, nuts, mounting
brackets or a loose compressor clutch assembly.
Drive belts are speed sensitive. At different engine speeds and dependingupon drive belt tension, drive belts can
develop noises that are mistaken for an A/C compressor noise. Improper drive belt tension can cause a misleading
noise when the compressor clutch is engaged, which may not occur when the compressor clutch is disengaged.
Check the accessory drive belt condition and tension as described in Cooling before beginning this procedure.
1. Select a quiet area for testing. Duplicate the complaint conditions as much as possible. Turn the A/C compressor
On and Off several times to clearly identify the compressor noise. Listen to the A/C compressor while the clutch
is engaged and disengaged. Probe the A/C compressor with an engine stethoscope or a long screwdriver with
the handle held to your ear to better localize the source of the noise.
2. Loosen all of the compressor mounting hardware and retighten. Check thecompressor clutch retainer. Be certain
that the clutch field coil is mounted securely to the A/C compressor, and that the clutch plate and pulley are
properly aligned and have the correct air gap (Refer to 24 - HEATING & AIR CONDITIONING/CONTROLS/
CLUTCH-A/C COMPRESSOR - INSTALLATION).
3. To duplicate high-ambient temperature conditions (high head pressure), restrict the air flow through the A/C con-
denser. Install a manifold gauge set or a scan tool to be certain that the discharge pressure does not exceed
2760 kPa (400 psi).
4. Check the refrigerant system plumbing for incorrect routing, rubbing or interference, which can cause unusual
noises. Also check the refrigerant lines and hoses for kinks or sharp bendsthat will restrict refrigerant flow, which
can cause noises (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - DESCRIPTION - REFRIGER-
ANT LINES).
5. If the noise is from opening and closing of the high pressure relief valve, recover, evacuate and recharge the
refrigerant system (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - STANDARD PROCEDURE -
REFRIGERANT SYSTEM RECOVERY), (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - STAN-
DARD PROCEDURE - REFRIGERANT SYSTEM EVACUATE) and (Refer to 24 - HEATING & AIR CONDITION-
ING/PLUMBING - STANDARD PROCEDURE - REFRIGERANT SYSTEM CHARGE). If the high pressure relief
valve still does not seat properly, replace the A/C compressor (Refer to 24- HEATING & AIR CONDITIONING/
PLUMBING/COMPRESSOR-A/C - REMOVAL).
6. If the noise is from liquid refrigerant slugging in the A/C suction line,replace the A/C accumulator (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/ACCUMULATOR-A/C - REMOVAL) and check the refrigerant oil
level and the refrigerant system charge (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING/REFRIG-
ERANT OIL - STANDARD PROCEDURE - REFRIGERANT OIL LEVEL) (Refer to 24 - HEATING & AIR CON-
DITIONING/PLUMBING- STANDARD PROCEDURE - REFRIGERANT SYSTEM CHARGE).
7. If a slugging condition still exists after replacing the A/C accumulator, then replace the A/C compressor (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING/COMPRESSOR-A/C - REMOVAL) and repeat Step 1.
REMOVAL
3.7L/4.7L ENGINES
WARNING: Refer to the applicable warnings and cautions for this system before performing the following
operation (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - WARNINGS) and (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - CAUTIONS). Failure to follow the warnings and cautions could result
in possible personal injury or death.
NOTE: The A/C compressor may be removed and repositioned without disconnecting the refrigerant lines or
discharging the refrigerant system. Discharging is not necessary if servicing the compressor clutch, clutch
coil, engine, engine cylinder head or the generator.

1. Recover the refrigerant from the refrigerant system
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - STANDARD PROCEDURE -
REFRIGERANT SYSTEM RECOVERY).
2. Disconnect and isolate the negative battery cable.
3. Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/BELTS-DRIVE -
REMOVAL).
4. Remove the nuts (4) that secure the A/C suction
line (5) and the A/C discharge line (9) to the A/C
compressor (6).
5. Disconnect the refrigerant lines from the A/C com-
pressor and remove and discard the seals.
6. Install plugs in, or tape over all of the opened
refrigerant line fittings and the compressor ports.
7. Loosen the bolt (5) that secures the bracket (7) to
the accessory mounting bracket (4).
8. Remove the three bolts (1, 6 and 3) that secure the
A/C compressor (2) to the accessory mounting
bracket.
9. Remove the A/C compressor from the engine
compartment.
5.7L ENGINE
WARNING: Refer to the applicable warnings and cautions for this system before performing the following
operation (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - WARNINGS) and (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - CAUTIONS). Failure to follow the warnings and cautions could result
in possible personal injury or death.
NOTE: The A/C compressor may be removed and repositioned without disconnecting the refrigerant lines or
discharging the refrigerant system. Discharging is not necessary if servicing the compressor clutch, clutch
coil, engine, engine cylinder head or the generator.

1. Recover the refrigerant from the refrigerant system
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - STANDARD PROCEDURE -
REFRIGERANT SYSTEM RECOVERY).
2. Disconnect and isolate the negative battery cable.
3. Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/BELTS-DRIVE -
REMOVAL).
4. Disconnect the wire harness connector from the
clutch field coil connector on top of the A/C com-
pressor (6) and the A/C pressure transducer (8) on
the A/C discharge line (1).
5. Remove the nuts (4 and 7) that secure the A/C dis-
charge line and the A/C suction line (5) to the A/C
compressor.
6. Disconnect the refrigerant lines from the A/C com-
pressor and remove and discard the O-rings and
dual plane seals.
7. Install plugs in, or tape over all of the opened
refrigerant line fittings and the compressor ports.
8. Remove the generator support bracket from the
front of the engine (Refer to 8 - ELECTRICAL/
CHARGING/GENERATOR - REMOVAL).
9. Remove the three bolts (1 and 3) that secure the
A/C compressor (2) to the mounting bracket (4).
10. Remove the A/C compressor from the engine
compartment.
5.9L DIESEL ENGINE
WARNING: Refer to the applicable warnings and cautions for this system before performing the following
operation (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - WARNINGS) and (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - CAUTIONS). Failure to follow the warnings and cautions could result
in possible personal injury or death.
NOTE: The A/C compressor may be removed and repositioned without disconnecting the refrigerant lines or
discharging the refrigerant system. Discharging is not necessary if servicing the compressor clutch, clutch
coil or engine.

1. Recover the refrigerant from the refrigerant system
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - STANDARD PROCEDURE -
REFRIGERANT SYSTEM RECOVERY).
2. Disconnect and isolate the negative battery cable.
3. Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/BELTS-DRIVE -
REMOVAL).
4. Remove the bolt (1) that secures the A/C suction
and discharge line assembly (2) to the A/C com-
pressor (3).
5. Disconnect the refrigerant line assembly from the
A/C compressor and remove and discard the seals.
6. Install plugs in, or tape over all of the opened
refrigerant line fittings and compressor ports.
7. Disconnect the wire harness from the clutch field
coil wire lead connector (4).
8. Remove the four bolts (1) that secure the A/C com-
pressor (2) to the mounting bracket (3) located on
the right side of the cylinder block (4).
9. Remove the A/C compressor from the engine
compartment.
8.3L ENGINE
WARNING: Refer to the applicable warnings and cautions for this system before performing the following
operation (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - WARNINGS) and (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - CAUTIONS). Failure to follow the warnings and cautions could result
in possible personal injury or death.
NOTE: The A/C compressor may be removed and repositioned without disconnecting the refrigerant lines or
discharging the refrigerant system. Discharging is not necessary if servicing the compressor clutch, clutch
coil or the engine.

1. Recover the refrigerant from the refrigerant system
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - STANDARD PROCEDURE -
REFRIGERANT SYSTEM RECOVERY).
2. Disconnect and isolate the negative battery cable.
3. Remove the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/BELTS-DRIVE -
REMOVAL).
4. Disconnect the wire harness connector from the
A/C compressor clutch coil connector (4).
5. Remove the bolts (5) that secure the A/C suction
line (1) and the A/C discharge line (3) to the A/C
compressor (2).
6. Disconnect the refrigerant lines from the A/C com-
pressor and remove and discard the seals.
7. Install plugs in, or tape over all of the opened
refrigerant line fittings and the compressor ports.
8. Remove the four bolts (1) that secure the A/C com-
pressor (2) to the cylinder block (3).
9. Remove the A/C compressor from the engine
compartment.
INSTALLATION
3.7L/4.7L ENGINES
NOTE: If a replacement A/C compressor is being installed, be certain to check the refrigerant oil level. See
Refrigerant Oil Level in this group for the procedures. Use only refrigerant oil of the type recommended for
the compressor in the vehicle.

CONDENSER-A/C
DESCRIPTION
The A/C condenser is located in the front of the engine compartment behind the grille. The A/C condenser is a heat
exchanger that allows the high-pressure refrigerant gas being dischargedbytheA/Ccompressortogiveupitsheat
to the air passing over the condenser fins, which causes the refrigerant tocool and change to a liquid state.
OPERATION
When air passes through the fins of the A/C condenser, the high-pressure refrigerant gas within the A/C condenser
gives up its heat. The refrigerant then condenses as it leaves the A/C condenser and becomes a high-pressure
liquid. The volume of air flowing over the condenser fins is critical to theproper cooling performance of the A/C
system. Therefore, it is important that there are no objects placed in front of the radiator grille openings at the front
of the vehicle or foreign material on the condenser fins that might obstruct proper air flow. Also, any factory-installed
air seals or shrouds must be properly reinstalled following radiator or A/C condenser service.
The A/C condenser cannot be repaired and, if faulty or damaged, it must be replaced.
REMOVAL
3.7L/4.7L/5.7L ENGINES
WARNING: Refer to the applicable warnings and cautions for this system before performing the following
operation (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - WARNINGS) and (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - CAUTIONS). Failure to follow the warnings and cautions could result
in possible personal injury or death.
1. Recover the refrigerant from the refrigerant system
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - STANDARD PROCEDURE -
REFRIGERANT SYSTEM RECOVERY).
2. Disconnect and isolate the negative battery cable.
3. Disconnect the A/C discharge line and the A/C liq-
uidlinefromtheA/Ccondenser(Referto24-
HEATING & AIR CONDITIONING/PLUMBING/
LINE-A/C DISCHARGE - REMOVAL) and (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING/
LINE-A/C LIQUID - REMOVAL).
4. Disconnect the wire harness connector (8) from the
A/C condenser cooling fan motor (7).
5. Remove the two bolts (1 and 9) that secure the
A/C condenser to the front upper crossmember (2).
6. Carefully lift the A/C condenser and cooling fan assembly to disconnectthe lower mounting tabs (6) from the
lower mounting flanges (3) and remove the assembly from the engine compartment.
7. If required, place the A/C condenser and the cooling fan assembly on a workbench and remove the four screws
(4 and 5) that secure the cooling fan to the A/C condenser and separate the fan from the condenser.
5.9L DIESEL ENGINE
WARNING: Refer to the applicable warnings and cautions for this system before performing the following
operation (Refer to 24 - HEATING & AIR CONDITIONING/PLUMBING - WARNINGS) and (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - CAUTIONS). Failure to follow the warnings and cautions could result
in possible personal injury or death.