A/C Less Time Delay

Fault-tracing Hints

As a general rule, the supply to the unit is live when the ignition switch is in the drive position. If none of the components is faulty, check the cable harnesses, connectors and earth connections.

Compressor 170 and Radiator Fan Motor 37

1. Check fuses 6 and 25 and check that the supplies to AC switch 169 and relay 156 are live.

2. Press the AC switch. Measure the voltage across pressure switch 166 (the pressure switch should be closed). Note that refrigerant will spray out when the pressure switch is disconnected.

Caution: Risk of frostbite.

3. Check cycling clutch contact 171. (It should close at +6 °C or 43 °F.)

4. Check that the relay is energised and that the relay contacts (87 and 87B) are live. If not, check that the coil/electronics are being supplied from thermostat 171 and from the +15 distribution terminal. When the relay is energised, terminal 16 should be live. At full throttle, terminal TK should be earthed.

5. Check that the supplies to the compressor and the radiator fan are live. (Temperature switch 168 should be closed.)

CU14 Fuel System

4. Check that pin 21 of control unit 200 is live and that relay 156 is earthed from pin 36 of the control unit.

5. Check that the supplies to the compressor and the radiator fan are live. (Temperature switch 168 should be closed.)

AC Radiator Fan 172

1. Check fuse 6 and check that the supplies to the AC switch and to relay 155 are live.

2. Press the AC switch. Measure the voltage across pressure switch 166 (the pressure switch should be closed). Note that refrigerant will spray out when the pressure switch is disconnected.

Caution: Risk of frostbite.

3. Check that relay 155 is energised and that the supply to the AC radiator fan is live.

Recirculation

1. Check fuse 6 and check that the supply to recirculation switch 143 is live.

2. Press the switch and check that the recirculation valve is activated.