AC problems on a 1990 GSX
 

I have a 1990 GSX that I have had for almost 20 years now. The AC recently leaked so with a friend who is a mechanic, we converted it to the 134. The compressor was leaking so rather than putting in new gaskets, which would have been smarter, I replaced it. The seals have been replaced and everything is good with a temp down into the 40's.

The problem is, is that it won't cycle. The compressor will come on, when the engine is up to temp but after a couple of minutes the fan stops so of course the pressure climbs. I put a paper clip in the sensor to see if that was it and the fan does come back on and the temp out of the vent will go to almost 32 but of course without the sensor it won't cycle. So is it the sensor? The odd thing is that the fan goes off but the compressor stays on when the sensor is in the loop.

What I also don't understand is that before the R12 leaked out, the AC worked fine.

I guess it isn't an easy answer. Well a switch to manually turn the AC on and off would work as long as I don't run it too long and let it freeze up.

I would look at the various fan motor relays first. It sounds like everything is ok, because the compressor is staying on, but I don't know which sensor you are jumping...

Did the old compressor leak slowly or did the fan shut off and blow the pressure relief valve?

The relays are all ok but just to make sure I changed them out with some pulled ones. I think it is the sensor inside. I replaced the compressor but I think just the manifold seal was bad due to the high pressure. I recharged and get temps down to 32 out the vent now but no cycling. It works though and for going through Death Valley, that is what I want.

Now to someday fix the cruise control.