GMC Repair: 1995 GMC Sierra / Air Conditioning, gmc sierra, fuse panels

Question
I have a 1995 GMC Sierra 1/2 ton 4x4 126k Miles. The other day the AC started to cycle On and OFF rapidly and then quit completely. The blower still works but the AC light is out and the Defrost/Floor selector will not adjust anymore. I checked both fuse panels with no fuses found blown. Is it the module in the dash bad? Is it the AC Pump under the hood?  
I have access to multi-meter.
Please Advise.... Carl Lippens

Answer
It could be a number of things. It sounds like an electrical issue. I would check the circuit going into the high pressure cut-off switch for resistance to ground. This is the only circuit that get its power directly from the control head(dash module), and if it shorts then it will fry the control head. I have had 1 concern of this where it was acctually the switch grounding inside itself.
this osunds alot like that one as I remember, and if it is then if you put a new control head in your truck it will fry the new one as soon as the A/C turns on.