Heating system problem
QI have a 2008 Ford Fusion 1.4 petrol. The aircon was leak tested and re-gassed. The heater is on regardless of control setting. Aircon light comes on but no discernible effect. I can’t see the clutch engages at any point. I’m unsure how to proceed. Could a control cable have become detached? Is there a relay/fuse to check?
Steve Rhenius
AI would presume that when the system was re-gassed it was checked and was operating efficiently. This is important as the system will not operate if the gas pressure is too high, and so ensuring this was set correctly is an important point.
The following fuses should first be checked. In the facia fusebox numbers 4, 33 and 38 – but as the A/C light comes on, I would expect to find the fuses in good order.
The compressor clutch is operated via the engine control module via relay number 4 which is located under the bonnet. It is possible that the clutch in the aircon motor has failed and this can be checked using an ohm meter to ensure that the circuit from the relay to the compressor is not either shorted out or open circuit.
Other possible causes of the problem may be that the temperature control door in the heater unit is not operating, or one of the sensors in the system is faulty.
The climate control system on your Fusion should incorporate a selfdiagnosis system which will display faults via the display and this can be activated as follows:
▶ Ensure the vehicles battery is fullycharged and turn the ignition on.
▶ Briefly press the OFF and FOOTWELL buttons simultaneously for two seconds then press AUTO within 1.5 seconds. The self-diagnosis should begin during which time an animation will be seen in the display. Then any trouble codes will be flashed up as two 2-digit numbers, so code 9242 would indicate a problem with the air flap actuator – displayed as 92 then 42. If no faults are present, then all segments are illuminated. Fault codes can be cleared and the self-diagnosis is ended by pressing DEFROST.
I can let you have an explanation of any codes retrieved.