Hello thirdgen forum, I've been lurking around for a while but now it's come time for my first post. I have searched and read many threads here but still cannot find the solution. I apologize if I missed something or there's an easy fix!

I have a 1986 Camaro. The AC system is retrofitted to R134a. Last summer I refilled the system with two or three cans of refrigerant to improve cooling and to stop the compressor from cycling on and off so frequently, but while I was off in college this past school year my car sat "in storage" for several months, and when I started her up the AC no longer worked (the vents blew ambient temp air). I tried Norm, Max, and Defrost modes.

Because the compressor clutch did not engage, my first thought was that the refrigerant simply leaked out. I measured the low-side pressure and it was indeed low so I started to refill the system with R134a and all of a sudden the pressure seemed normal again, or even high, so I stopped refilling. The compressor clutch still did not engage (not even once). With normal pressure readings and a clutch that still did not engage, I suspected something else must be wrong.

Searching the forums more I decided to jump the pressure switch connection on the accumulator/drier. This caused the compressor clutch to engage and it ran fine so the problem couldn't have been a connection to the compressor itself.

I figured the problem might have been the pressure sensor clutch cycling switch (the connection I jumped) after reading this so I bought a replacement at Autozone and installed, but it made no difference. This is where I'm stuck.

Any ideas would be greatly appreciated. Thanks in advance.

 

im no ac master but the low side sits at 100 psi when the car is off and outside temp is 90+ if i where you i would charge it to 55 psi and if that doesnt work theres a screw in the middle of the pressure swich where you jumped the wires, turning it to the left should lower the pressure needed to start the compresser. btw have you put any super seal in b4 it was stored.... and if none of this works a toggle swich to the compresser is what i would do if you live in a hot place like me

 

I've never put any super seal or anything in it. I'll go ahead and charge it to about 55 psi and see what happens. Is there any harm in charging the system too much? I'll also fiddle around with the screw if that doesn't work. I'll update whether anything worked or not.

 

Could be just a bad diode:

https://www.thirdgen.org/forums/cool...-c-clutch.html

 

Jump the pressure cycling switch connecter and verify that you have sufficient refrigerant. If the issue continues check the wiring and pressure cycling switch connecter. It sounds like that is where your problem may be.

 

I will check that pressure diode as well as further investigate the pressure cycling switch. Hope I find the solution because I don't want to take it to a mechanic yet and it's getting hotter and hotter.

 

I understand, Florida seems to be getting hot early this year. I ran into a similar problem to yours a few weeks ago. I kept blowing the blower fuse when ever I turned the ac on. My problem was the high pressure cutout switch had melted and shorted out. You could always try what I did and start with the ac controls in the dash with a multimeter and start checking the harness all the way through to the pump.

If I may suggest, if you haven't already I would replace your original tube and fin condenser with a 6mm condenser, it definitely makes a difference it warmer climates.