veleno

How can I tell if the a/c system has been upgraded to 134a or is still r12? I picked up the car and the compressor is not turning on so I want to see if I add freon will it turn on and for how long. What I don't want to do is fill it with the wrong type of freon.

There are no stickers for the retrofit and the prior owner doesn't know either.

Might be easier to go to the a/c shop and have them convert the whole thing but before I do that I want to give it a try.

joejoe

Look at the high/low fittings. If they are 1/4" (and the same) then r-12. If quick release type (they will be different sixes) then 134. Hope this helps.

seafeye

Maybe this will help. You can just see by the size of the fitting.

carlege

Does that include converted systems?

Arominus

The fittings will likely be the stock r12's, i know the PO was using adaptors to get 134 into the stock system as he gave them to me when i bought the car. So the connections wont tell you much unless they left the adaptors on it.

veleno

Good points on converted systems. That however doesn't make it any easier! haha

griffiths

If you want to check if the problem is possibly a low refrigerant issue you could either:
A) Ignition off: Unplug the clutch wire to the compressor, apply 12vdc to the clutch wire and see the clutch hub plate 'clicks' (moves in and out as power is applied or removed), or
B) Ign on, ac on: jump the low pressure switch