Q. I’ve had my Vauxhall’s air-conditioning regassed but it’s still blowing warm air. The pressure is fine.
A. Most garages have regassing equipment but not all bother to diagnose faults. It could be a faulty compressor or radiator cooling fan (or their circuitry).
Start the engine from cold with the air-con off. Ask someone to turn the air-con on while you stand by the open bonnet. You should hear the radiator fan start to run within a couple of seconds. Then you should hear a click, which is the compressor switching on. If either sound is missing, you know where the fault lies.
Note: if the fan is faulty, the system may still blow cold air when the car is moving, because air is flowing through the radiator.
TIM’LL FIX IT
Tim Shallcross used to train AA patrols to fix cars. Now he advises the Institute of Advanced Motoring — read more from Tim here.
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