Chevrolet Repair: airconditioning sys., gmc sierra, c button

Question
92 gmc sierra 5.7 auto..... a/c started to flash on climate control panel. manual stated a/c sys needs to be serviced. found that depressing a/c button does not start clutch on front of compressor. took jumper leads to clutch plug and it worked fine and i got lots of cold air in truck. tested plug to clutch and there is no power. the fuse is not blown. what am i missing ?

Answer
Hi Leo,
Sorry this answer is so late...I signed out on vacation, but the site doesn't seem to update all the areas I am in, even though it says it will.
In case you haven't gotten it yet, I would say that you Might need just a little freon. There is a low pressure switch that is intended to protect the compressor by not allowing the clutch to engage if it is low on freon.
There are other possibilities, but that is the first thing I would check.
If you still need help, write back.
Van