97 Volvo 850 T5, A\C dose not work. Freon Pressure is ok.
When I start the engine with A\C on, Compressor run for few seconds and turns off. Evean I turn the A\C switch on & off the compressor dose not work until I start the engine again. I did bypass the Low-pressure switch plug (by jumper wire)but still the same. Could this be a electrical problam? The repair guy can't figure it out. Please help me.
U J.

It certainly sounds like an electrical problem, if your refrigerant charge is OK.
With the engine running and the A/C switched on, have your repair guy check for power at the connector to the compressor. If there is power, he could try bypassing the superheat switch on the back of the compressor, or checking for power in the wire just before it goes into the clutch (he will probably have to stick a pin into the wire to do that test.) If bypassing the superheat switch doesn't do it, and there is power going to the clutch, the clutch is bad.

If there is no power at the compressor connector, he should check for power in and out of the A/C relay. If there is power in and not out, the relay is bad. If there is not power in (it should come in on 2 pins), then you will have to diagnose whether the computer is getting a signal to turn on the A/C or if you have a computer problem.

Thank you Peter. I will try the way you describe And give you the result.
Uj