I have a 92 Vette that was my dads and it had the conversion to the 134a done. The AC was working when the car was parked and it has been sitting for a while. I had checked the pressue with a one of the do it your self refills, and the pressure seems to be fine but the compressor is not running. The issue I have is that the clutch does not engage when the AC is turned on. Is there away to test if it is the clutch or some other issue? I have service manuals but they are not for the 134a system.

You can hot wire the clutch to check operation , if it works then check relay next.

I have a 92 Vette that was my dads and it had the conversion to the 134a done. The AC was working when the car was parked and it has been sitting for a while. I had checked the pressue with a one of the do it your self refills, and the pressure seems to be fine but the compressor is not running. The issue I have is that the clutch does not engage when the AC is turned on. Is there away to test if it is the clutch or some other issue? I have service manuals but they are not for the 134a system.


Make up a short double ended 1/4" male spade terminal wire about 4" long and plug both ends into your pressure switch plug. That sends the 12 volt current straight to your A/C clutch coil; engaging the clutch.

I have a 92 Vette that was my dads and it had the conversion to the 134a done. The AC was working when the car was parked and it has been sitting for a while. I had checked the pressue with a one of the do it your self refills, and the pressure seems to be fine but the compressor is not running. The issue I have is that the clutch does not engage when the AC is turned on. Is there away to test if it is the clutch or some other issue? I have service manuals but they are not for the 134a system.
Just unhook the battery for a minute and the A/C programmer will reset and if it's got freon it will work.
David