A/C Components In Engine Compartment, Servicing

A/C Components In Engine Compartment, Servicing


NOTE: System components identified with an * must only be serviced or replaced after discharging refrigerant system. Use Kent Moore ACR4 or equivalent.







1 - Air intake duct, rear
2 - Vacuum reservoir
- Insert vacuum hose 30 mm (13/16 in.) into reservoir
- Vacuum hose layout
3 - Bulkhead opening for heater core and vacuum hose
4 - A/C thermoswitch -F45-
- Switching occurs between terminals -2- and -3- of thermoswitch
- Thermoswitch switches the coolant fan when coolant temperature increases, to third speed (on at 112 °C, off at 108 °C)
- Switching occurs between terminals -2- and -3- of thermoswitch
- Thermoswitch also switches the A/C clutch -N25- to a higher coolant temperature (off at 120 °C, on at 112 °C)
- Removing and installing See Fig. 4
5 - Evaporator water drain hose with valve
- Removing and installing See Fig. 2
6 - Relays
- For exact relay location and wire routing (1992- 1999)
7 - Individual fuses for coolant fan - S42- (2x)
8 - Coolant Fan Control (FC) series resistance -N39-
9 - Condenser*
10 - A/C clutch -N25-*
11 - Pressure relief valve*
- Protects refrigerant circuit from excessive pressure
- Checking See Fig. 5
12 - Receiver drier*
13 - A/C pressure switch -F129-
- Checking See Fig. 3
- Removing and installing:
- Tightening torque 8 Nm
- Replace O-ring seal (note part number)
14 - Sight glass*
15 - Service valves*
16 - Expansion valve*
- Ensure valve is protected from rain and splash water
- Ensure insulator is in good condition See Fig. 1


NOTE: System components identified with an * must only be serviced or replaced after discharging refrigerant system. Use Kent Moore ACR4 or equivalent


Fig. 1 Expansion valve insulator, checking







1 - Expansion valve
2 - Insulator

The insulator protects the expansion valve against high engine compartment temperatures to prevent a decrease in A/C system cooling performance.

Fig. 2 Evaporator water drain hose and valve, removing and installing







1 - Hose
2 - Valve
Remove engine
Remove sound dampener from bulkhead
Remove glove compartment
Remove floor outlet console
Valve -2- is pushed on hose -1-

Fig. 3 A/C pressure switch -F129-, checking







- Ensure O-ring (10.8 mm x 1.8 mm) fits properly in groove

Functions

Switch (between the blue wires) controls the A/C clutch -N25- when pressure in refrigerant circuit is too high or if system not charged properly:
- Switch opens (compressor OFF): below 2.0 bar (29.0 psi)
- Switch closes (compressor ON): above 3.0 bar (43.5 psi)

Checking switch:

- Briefly bridge connections from terminal 1 and 2 of connector with engine running. If A/C clutch switches on -N25-, refrigerant circuit is empty.
- Closes when over 16 bar gauge pressure and opens again when under 12.5 bar gauge pressure (threshold voltage)
- R-134a pressure switch is identified with a green label or lettering "For R-134a"

Fig. 4 A/C thermoswitch -F45-, removing and installing







CAUTION!
Relieve cooling system pressure before removing A/C thermoswitch.


- Refill coolant after thermoswitch installation

1 - A/C thermoswitch -F45-
2 - O-ring
3 - Clip
4 - Coolant hose

Fig. 5 Pressure relief valve on compressor, checking







- Protects against excessive system pressure
- At approximately 40 bar (580 psi) the valve opens to relieve system pressure then closes again when pressure has dropped. The refrigerant system does not discharge completely
- Located on receiver drier

The plastic washer -arrow- will break if the pressure relief valve releases (opens)