The ac was working a week ago when I drove it. My wife borrowed my car (she likes it better than the minivan)and called me on her cell and asked, "Why isn't your ac working?" Big surprise to me.

I checked some real basic things at first like is the compressor even engaging. It wasn't. Next I checked the freon level. The freon charge was in the yellow, so it had freon in the system and perhaps too much. I do remember charging it last year for the first time. I added about half a can and it only went into the blue at that time which indicated a full charge. So the charge being in the yellow was a surprise to me. Any connection?

I also found the odd shaped box of relays on the driver's side near where the brake resevoir is and found the ac relay. It was the same yellow color and number as the one to the left of it. I swapped them and started the car with no change.

I think you mentioned another relay behind the glove box. A buddy of mine and I changed out the heater core a month ago and I did pull out the glove box to get better access to drop the panels. Though the ac worked after that, perhaps that relay has broken since then.

I could access the ECC switch by pulling out the stereo, but how would I test that? Or is there a switch it could be "switched" with?

Thanks for the advice and patience.