Why do I keep burning up A/C clutches
 

I have a 1972 Chevelle with factory A/C. I have burned up 5 A/C compressor clutches and can't figure it out. I have converted the POA valve to a update kit specifically for the 134A. I have installed a Pro6ten compressor (Burned two of them), changed the Expansion Valve. I just don't know that much about the A/C system to know what to look for. I don't really trust my car at any A/C shop. Does anyone have an idea for me?

Wish I knew more about AC, but this question is out of my area of expertise

Look in the motor forum. I think that there is a thread about air conditioning and the clutches.

I never saw it.

OK..here is the link to when I had a question about replacing the fan clutch when I had my a/c installed. Brian states how there are 3 different clutches. That might be your problem, maybe you are using the wrong one. Check out the thread. Good Luck and I hope this helps.

http://chevelleforum.org/showthread....tioning+clutch

That discussion was about cooling fan clutches, not AC clutches. The AC clutch is an electro-magnetic clutch. Only thing I can think of is voltage. Have you checked your alternator output voltage, especially at higher rpm? You may have a bad voltage regulator allowing the voltage to go to high and burn up the clutch. Voltage should be 14 to 14.5 volts.

Thanks for the replys. I discovered I had a build up of compressor oil in the evaporator. I blew it out and now it works perfect.