when I turn on the a/c my "service a/c" light comes on [but then goes out after switching to Econ mode] and compressor clutch will not cycle. Heat also will not work. Have checked freon level, fuses and relays. When I ground the a/c relay, clutch will cycle and a/c will cool-service light stays on under this condition.
I have just advertised this car for sale so I need a quick fix, Help!!
Scot

PS: I am a mechanic by trade, but automatic climate controls are not my forte' . Technical answers are fine by me....

You Have A Freon Leak That Has Plugged The A/c Condensor Core. All Air Goes Through This Core Befre Going Anywhere.the Freon Coats The Coil Dust Plugs It.remove Core Sell Without A/c.

No,no,no,no!
First check both the high and low pressure switches, just jumper the plug and see if compressor runs, if it runs while the jumper is in, then that particular switch is bad.
You can then put in a new switch & cure the problem.
If this does not work, check the relay, about $3.99 at Auto zone.
Your problem appears to be electrical in nature, not mechanical.

the car is gone and it's the dealer's problem now. I do appreciate the attempts to diagnose the problem. It definetly was electronic in nature, and I suspected the module/computer after eliminating everything else in the system.

In case you see this problem again the first thing to do is to reset the climate control. I had the same exact problem and checked everything before getting advice form a bulletin board. Disconnected the negative battery terminal for about 3 minutes and the climate control worked fine again. Of course, you could have another problem but start with the easy things first. Hope you got your money out of the car you sold.