A/C System W/Time Delay
A/C Diagrams:
A/C Components:
Locations of components
3 Earthing point
In the fascia
7 Earthing point, radiator cross-member
8 Lighting relay
In the electrical distribution box in the engine compartment, relay positions A and B.
17 Extra rheostat for the lighting of switches and controls
On the left-hand side of the fascia
22A Fuse holder
In the electrical distribution box, in the engine compartment, on the left-hand wheel housing
37 Radiator fan motor (ordinary)
On the right-hand side of the radiator package
38 Recirculation valve
Under the fascia on the right-hand side, forward of the right-hand A pillar
59 2-pole connector
One adjacent to radiator fan 37 one adjacent to AC radiator fan 172
60 Single-pole connector
One at the extreme rear of the engine compartment, at the compressor
One at the back seat, for connecting the AC
67 6-pole connector
In the engine compartment, on the right-hand side, at the air intake
113 Relay/time delay relay for the electrically heated rear window
In the electrical distribution box in the engine compartment, relay position C
116 Switch for the electrically heated rear window
On the fascia
142 Solenoid valve for raising the idling speed, AC
On the engine, on the by-pass hose of the throttle housing
143 Recirculation switch, AC
In the centre of the fascia
152C 29-pole black connector
In the electrical distribution box in the engine compartment, on the left-hand wheel housing. The connector is accessible from the interior of the car.
155 Relay for the AC radiator fan
In the electrical distribution box in the engine compartment, relay position J
156 Relay for the AC compressor
In the electrical distribution box in the engine compartment, relay position H
158 Negative distribution terminal
In the electrical distribution box in the engine compartment, on the left-hand wheel housing
166 Pressure switch for the AC radiator far
In the engine compartment, on the drying agent container, forward of the right-hand wheel housing
168 Coolant temperature switch, AC
On the radiator inlet hose, near the distributor
169 Switch,AC
In the centre of the fascia
170 Compressor for the AC
At the rear of the engine compartment
171 Anti-freeze thermostat (cycling clutch contact) for the AC
Under the fascia, forward of the right-hand A pillar
172 Radiator fan for the AC
On the left-hand side of the radiator package
173 Diode for the AC compressor
In the cable harness, at the rear of the valve cover
200 Control unit for the LH/CU14 fuel system
Forward of the right-hand front door, below the fascia (behind the trim)
201 Engine earthing point
At the engine lifting lug
203 Throttle angle transmitter for the LH fuel injection system
On the engine throttle housing
F Relay position F
G Relay position G
In the engine compartment, in the electrical distribution box
Operation
Certain cars are equipped with an Air Conditioner (AC). For a complete description of the wiring for the lighting of switches on cars for the US, CA and JP markets, see the section entitled "Lighting for controls - US, CA, JP".
Compressor 170 and radiator fan motor 37
The AC can be switched on and off by means of AC switch 169, which is supplied from fuse 6, via black 29-pole connector 152C. When the switch is depressed, the lamp built into the button will be supplied directly (not via the resistor), so it will light up with full intensity. (When the switch is not activated, the lamp is supplied via fuse 6.)
Compressor 170 and ordinary radiator fan 37 are connected via relay 156, whose contacts are supplied from fuse 25. The relay wilt be energized when the following conditions have been satisfied:
- Pressure switch 166 is closed, i.e. the refrigerant pressure is at least 2.8 bar.
- Anti-freeze thermostat (cycling clutch contact) 171 is closed, i.e. the ambient temperature is at least about +6°C.
When the relay is energized, power will be supplied to the compressor only if temperature switch 168 is closed. (The switch will open if the engine temperature should exceed about +115°C.)
Diode 173, which is connected in parallel with the compressor, reduces the voltage transients at the instant when the compressor is switched off (1989 model).
Delayed connection when starting
Relay 156 is equipped with two time delay functions. One of these is activated whenever the engine is started. Ignition switch 20 (in the start position) supplies pin 50, and if switch 169 is then depressed, the energizing of the relay and thus starting of the compressor will be delayed by about 10 - 20 seconds (depending on the engine variant), to ensure that combustion in the engine will be stable after starting, before the the AC load is applied.
Idling speed compensation and cut-out at full load
Cars without A/C valve
Solenoid valve 142, which is kept open when the compressor is running, is used for idling speed compensation for the increased load caused by the AC.
Cars with A/C valve
On certain variants, the auxiliary air valve is replaced by an Automatic Idling Control (AIC) valve which also compensates for instantaneous load increases at idling speed.
The control unit receives a signal via relay pin 16 when the time delay of the relay is activated, and it then starts idling speed compensation. After 0.3 seconds, the relay will be energized and the compressor will start. The relay electronics receive their supply (in the drive position) via pin 15.
When the engine is running at full throttle, pin TK of the relay will be earthed through throttle angle transmitter 203, and the relay will trip the compressor.
AC radiator fan 172
Extra radiator fan 172 for the AC is connected via relay 155 and is supplied from fuse 6.
The relay coil is supplied from the contacts of relay 156 and from pressure switch 166. The AC radiator fan thus runs when AC switch 169 is depressed and pressure switch 166 is closed.
Recirculating valve 38
Recirculation valve 38, which controls the recirculation damper, will be switched on when recirculation switch 143 is depressed. The switch is supplied from fuse 6. When the switch is depressed, the lamp built into the switch will light up with full intensity.