i bought a 94 Z28 two months ago the ac was very cold up until now it just blows out hot air i parked it two weeks ago the air was working drove it two days ago no air i checked the refrigerant which was full the compressor comes on if put wire in place of the relay same for the fans but still hot air with both on please help me this has got me stumped,thanks

 

How did you check the refrigerant?

 

This doesn't belong in the Ask GM section. Moving you to 4th gen.

 

I checked with a gauge on the low pressure service port

 

Depending on what gauge you used, some won't tell you how much refrigerant is in the car until you start adding some from a can.

 

That's what i did

 

Maybe your plenum doors arent working correctly. I know they need vacume to work properly. I think theres a hard plastic line on the manifold that feeds the vacume for the plenum door operation.........

 

Ok I'll try that tomorrow thanks

 

Check the back of your thermostat panel. If that plastic clip breaks or slips it could be stuck on heat on the back side if your constantly changing the temp settings.