BMW: 98 BMW 328IS Stalls when AC is on, 1998 bmw 328is, bmw 328is

Question
I know this is not your area of expertise but maybe you can help me.  My 1998 BMW 328IS (60,000 miles) stalls at stops only when the AC is on.  There are no lights or codes displaying the cause of the problem.  Therefore, it can't be diagnosed with a computer check.  Do you know what could be causing this problem?

Answer
Angele,
 Well you have relatively low mileage for a vehicle of that age, so I dont think the anything is worn.
 
 I'll give you a run-down on how the A/C works.  You have a compressor that "compresses" the freon and makes it cold.  This compressor is driven by a belt, like the alternator.  When the A/C is switched off, the pulley on the compressor spins freely, with no drag on the engine.  When you switch the A/C on, a "Clutch" activates and makes the pulley turn the compressor.  It takes quite a bit of effort to turn this compressor, and it's hard for the engine to do this.  Under normal operation the cars computer (ECU) will electronically adjust the idle when the A/C is on.  That way it will still be idleing at the same RPM, even though there is more load on the engine.  

 My guess is that you're ECU is never getting the signal that the compressor is on, and it never idles the engine up.  This would lead to a stall like you are having problems with.  So have someone check the wiring and sensors (there are numerous sensors in the A/C system).

 Hope this helps,
 Josh

 P.S. Also have someone check the compressor, it might be extremely hard to turn and even with the engine idleing up, it's still not enough.