Engine Compartment Components
A/C Refrigerant System (R-134a) Components, In Engine Compartment
Note: Discharge A/C system before removing components marked with an asterisk (*)
1 - Expansion valve*
- ensure valve is protected from rain and splash water
- ensure insulator is in good condition ~ Fig. 6
2 - Plenum tray
3 - Evaporator water drain valve
- located behind firewall insulation
- removing/installing ~ Fig. 3
- valve flap must be clean and free of dirt, wax or undercoating - valve flap must close
4 - Heater core connections and vacuum hose
5 - Vacuum reservoir
- insert vacuum hose 30 mm (1 3/16 in.) into reservoir
- removing/installing ~ Fig. 7
6 - Vacuum hose
- vacuum hose layout Vacuum and Vapor Hose Diagrams
7 - Check valve
- arrow points toward vacuum source (engine)
8 - Fresh air/recirculating flap two-way valve (N 63)
- valve opens (allows vacuum to servo) when voltage is applied
- vacuum hose layout Vacuum and Vapor Hose Diagrams
- installing ~ Fig. 5
9 - Coolant Fan Control (FC) Control Module (J293)
- with fuse S88
10 - A/C cut-out thermoswitch (F163) and Third speed Coolant Fan Control (FC) Thermoswitch (F165)
- only on vehicles equipped with ECC-Diesel engine (Canada only) or 2.8L VR6 engine (code AAA)
- F165 switches coolant fan to 3rd speed as temperature increases - third speed on at 112°C (234°F), off at 108°C (226°F)
- F163 switches A/C clutch (N 25) off if coolant temperature is too high - A/C clutch off at 119°C (246°F), on at 112°C (234°F)
- removing/installing on vehicles equipped with 2.8L VR6 engine, code AAA ~Fig.1
11 - Condenser*
12 - Pressure relief valve*
13 - A/C clutch (N 25)*
14 - Receiver drier*
15 - A/C pressure switch (F129)
- functions Refrigerant Pressure Sensor / Switch
- checking ~ Fig. 2
- removing/installing:
- torque to: 8 Nm (71 in. lb)
- always replace O-ring (Note Part No.)
16 - Sight glass*
17 - Low pressure service valve
18 - High pressure service valve
19 - Ambient temperature switch (F 38)
- switches A/C clutch (N25) off at low ambient (outside) temperature - A/C clutch off at -1°C (30°F), on at 7°C (45°F)
- removing/installing ~ Fig. 4
20 - Air intake grill
Fig. 1 - A/C cut-out thermoswitch (F163) and Third speed Coolant Fan Control (FC) Thermoswitch (F165) Removing/Installing (vehicles with 2.8L VR6, engine code AAA)
CAUTION: Cooling system may be under pressure. Relieve system pressure. before removing any thermoswitches/sensors.
Note: Refill engine coolant to proper level after installing thermoswitch/sensor.
1 - Clip
2 - Thermostat housing
3 - 0-ring
4 - Thermoswitch (F163)/(F165), brown
5 - Engine Coolant Temperature (ECT) Sensor (G2)/After-Run Coolant Fan Control (FC) Thermoswitch (F87),yellow
6 - Engine Coolant Temperature (ECT) Sensor (G 62), blue
- relieve system pressure
- remove wire connector from F163/F165
- remove clip -1- and pull thermoswitch from housing
- install in reverse order of removal
- refill engine coolant to proper level
Fig. 2 - A/C pressure switch (F129), Checking
- ensure O-ring (color: red, 10.8 mm x 1.8 mm) fits properly in groove
- to remove, unscrew switch from Schrader valve; tightening torque: 8 Nm (71 in. lb)
Functions:
- switches A/C clutch (N 25) OFF if system pressure is too low (low refrigerant charge) - switching occurs between terminals 1 (T4a/1) and 2 (T4a/2)
- switch opens (compress6r OFF): below 1.2 bar (17.4 psi), switch closes (compressor ON): above 2.4 bar (34.8 psi)
- switches A/C clutch (N 25) OFF if system pressure is too high - switching occurs between terminals 1 (T4a/1) and 2 (T4a/2)
- switch opens (compressor OFF): above 32.0 bar (464.1 psi), switch closes (compressor ON): below 24.0 bar (348.1 psi)
- switches coolant fan (V 7) to second speed when A/C system pressure increases - switching occurs between terminals 3 (T4a/3) and 4 (T4a/4)
- switch closes (2nd speed ON): above 16.0 bar (232.0 psi), switch opens (2nd speed OFF): below 12.5 bar (181.3 psi)
If A/C clutch (N 25) does not engage with A/C ON,
- start engine
- using a jumper wire, briefly bridge terminals 1 (T4a/1) and 2 (T4a/2) of A/C pressure switch connector
If A/C clutch (N 25) now engages, refrigerant system is discharged (empty)
- check A/C system for leaks, repair as necessary
Note: With A/C Pressure Switch (F129) removed and connector attached, A/C clutch should not engage and A/C should not cool.
Fig. 3 - Evaporator water drain valve, removing/installing
1 - Firewall
2 - Evaporator housing
3 - Valve flap (shown lifted)
4 - Water drain valve
5 - 14 mm Allen wrench
- to remove, insert 14 mm Allen wrench -5- into valve, rotate valve 45° (1/8 turn) and pull from evaporator housing
- install in reverse order of removal
- after installation ensure valve flap closes
Fig. 4 - Ambient temperature switch (F38) removing/installing
- remove connector -2- from ambient temperature switch
- remove ambient temperature switch -1- in direction of arrow
Fig. 5 - Fresh air/recirculation flap two-way valve (N63), installed position
1 - Cap
Check air vent slot - must not be plugged
2 - Fresh air/recirculating flap two-way valve (N 63) (other designs possible)
Fig. 6 - Expansion Valve Insulator, Checking
1 - Insulator
2 - Expansion valve
Insulation is used around expansion valve to prevent moisture (condensation) build-up and to protect expansion valve from high engine compartment temperatures and the resulting decrease in A/C system cooling performance.
- install insulator -1- (arrow) onto expansion valve -2- as shown
- check insulator for damage and proper fit, replace if necessary
Fig. 7 - Vacuum reservoir, removing/installing
1 - Vacuum hose
insert into reservoir 3O mm (1 3/16 in.)
2 - Rubber grommet
3 - Vacuum reservoir
4 - Nut
5 - Wheel housing liner
- remove wheel housing liner
- remove vacuum hose -1- and nut -4- and remove reservoir
- install in reverse order of removal