[rbroccol]

1999 Buick Lesabre Custom 125K miles. Yesterday got in my car and went to lunch, AC was on and working, blowing cold air. 30 minutes later got back in my car, started it up, pushed "Max" AC button on, but now it is not blowing cold air. It's blowing only outside air as if I had the "Vent" button on. Lifted hood and noticed that the AC clutch on compressor was not engaged. I tried the "Defrost" button, but still compressor clutch did not engage. Also, when "Max" or "Defrost" button was on and I was looking under hood and noticing no AC clutch engagement, the two cooling fans were NOT on. I thought that when you turn on AC, the cooling fans would turn on, but maybe this is only if the compressor is running? I'm leaning towards a relay or blown fuse, but do not have the shop manuals or Haynes book to find out where the fuses or relays are located for the AC system. Can someone tell me where the fuses or relays for the AC system are? Also if it does not turn out to be a fuse or relay, any other ideas what might be the culprit? Doing some research, I know my car has an A/C clutch diode (not sure what that does, where it's located or how to test it). If this was not working properly, would it prevent the AC clutch from engaging? Thanks.