ok guys its not a truck but most a/c units have the same componets and switchs. its for my grandmothers car. its a 1992 thunderbird 3.8l POS. with a 134r conversion done to it. ive done all the normal checks of fuses, connections, and ohm ing all the switches . the clutch is not kicking on at all. there is no power going to the cluch switch to turn it on.. now all the switches omh' ed perfect accept for the switch on the condenser. it the larger round switch with a 2 prong connection on top, it omh'ed at 1.987. and was a little corroded. could this switch be the problem?? when this switch goes does it not allow power to cycle the clutch? im not sure what else it could be... im sure someone has had the same problem with there ford. thanks

 

Did you try jumping across the switch?

 

no i thought about it but didnt. i just gotta run 12v across the 2 prongs on the compressor switch right? it kind of confused me that there was no voltage going to the switch with all the fuses being good and the connections ok. and this car being never been tampered with and stupid clean for a 92. agian its an old persons car lol!!

 

put a jumper between the two terminals and see if compressor starts

 

ok ill give it a try

 

A switch on the condenser is a high pressure switch, it probably tells the fan to come on. I doubt it is your problem. Are you sure there is refrigerant in it?