Planning the next
AO Silver Member
Join Date: May 2007
Location: United Kingdom
Identify the aircon compressor ( between engine and radiator with two pipes attached to it )
Switch on engine.
Switch off aircon
Watch your fingers, loose clothing & long hair!
Look at compressor pulley. The part with the belt will be turning, but if you look closely, the centre part of the pulley will be stationary.
Switch on the aircon
If it's working correctly, you should hear a sharp 'clunk' and the centre of the pulley will now be turning with the belt.
If you hear a 'clunk' but the centre part of the pulley still doesn't turn, the compressor's clutch has failed.
If you don't get a 'clunk', either the compressor isn't getting 12v to energise the compressor's clutch OR you do not have sufficient refrigerant pressure in the system.
If you have a multimeter, test for 12v by disconnecting the compressor from the 12v supply at the connector on the compressor. Connect the car side of the connector to the multimeter and see if you get 12v with the engine running and aircon on. If you don't have a multimeter, try connecting a low wattage 12v bulb between the connector and the car body. It should light with 12v present.
If you get 12v at the compressor, it is likely that the refrigerant pressure has fallen below 2.45 bar. You need to get the system leak tested/re-gassed.
Last edited by pkr; 28-05-12 at 08:46.