m3 ac compressor problems
 

I had to replace the air conditioning compressor on my ladys 97 m3 last season, The problem I am having is that the air works fine at idle, however , above 2000 rpm the compressor cuts out and no longer works, after I come to a stop, if i shut off the ac button , and turn it on again, walla!! cold ac again. I was wondering if anyone has seen this before. Could the ac panel cause a problem like this???

What are your refrigerant pressures at 2000 rpm?

When your motor is turning more RPM, it is creating increased refrigerant velocities, thus lower suction pressures.

If your System is low on refrigerant it would cycle off on the low pressure cut out switch when you rev the engine.

The only thing that puzzles me is the fact that you have to reset it manualy. The ones I am familiar with have automatic reset pressure controls,In other words when you are at idle the system pressures return to normal operating pressures and it will start cooling on its own.

But All the same, put a pressure gauge on the low side and rev the engine to see if it drops below the low pressure setting printed on the side of the green control mounted on the receiver dryer. If so, you may only need to add a little refrigerant.