Aircon failure

Q When I start my 2006 Ford Mondeo 1.8 petrol with 142,000 miles after it has been standing for a number of hours, the aircon only works for a few minutes then shuts down. When the car starts, I can see that the clutch on the compressor pulley has engaged, but it disengages after a few minutes. If I hit the pulley with a stick while the engine is running, it sometimes engages for a short while, then shuts down. The system has been regassed and does not have any leaks.

Could this be a problem with a sensor or a faulty clutch. If it’s the clutch, can this be changed without degassing the system and removing the compressor? I suspect that the cost of renewing the compressor and receiver/dryer will be more than the value of the vehicle.

David Turner

A The air gap of the pulley is adjustable. It may be the case that if this is adjusted then the clutch will operate correctly. This can be done without degassing the system and removing the compressor.

The clutch gap should be 0.35-0.75mm and is adjusted by removing or fitting spacer washers between the driveplate and pulley. The driveplate can be removed by undoing the centre fixing nut.

I would also inspect the electrical terminal to the compressor, in case the action of hitting the pulley is actually having an indirect effect on the connection and restoring the operation.

If a new compressor is required, this company can supply a new unit for £136.74 – autoairconparts.co.uk – although, not having used this company, this is only a suggestion and not a recommendation.