The car A/C works just fine, except for when it gets stuck in a traffic jam for more than 10 min. Then the A/C blows out warm air despite the compressor light still being on. The engine has then to be shut down for at least an hour to have the A/C running properly again.

I took it to the dealer and they said that the compressor has to be replaced at a cost of 22,000 baht. I think they are being too drastic.

Any ideas? I soon might have to seek a second opinion from another A/C repair shop.

I had a similar problem. You may have an engine overheat problem or a faulty switch.

In my cars a/c system there is a cutout (thermal protector) switch located on the compressor that activates whenever the engine starts to heat up. Basically this switch stops the compressor loading the engine, the a/c light stays illuminated.

My car had been modified to use electric radiator fans and the fans only started working at a higher temperature to the switch activation in the a/c system.

The problem was solved by modifying the radiator cooling fans so they operated all the time during a/c operation.

Before changing out the compressor have them simply top of the refrigerant, it may be low.

Also, when the ac starts blowing warm air, check to see if the compressor is actually running, (drive pulley is engaged), if not replace the high and low side pressure switches which are fairly cheap before replacing the compressor, (usually the switches are seated in quick-change fittings so you won't lose any refrigerant).

I took the car down to Hua Hin and back to Bangkok (about 400 km.) and had no probelems whatsoever. The A/C cooled the car perfectly fine since the traffic was quite light. The temp. gauge showed normal engine temperature.

But thanks both for your replies. I will have the refrigerant levels checked first.