greg69jones

Good afternoon all! I just recently bought me a 1984 Firebird V8 5.0L 305! Got it for $1200 with no rust and great running engine/auto trans! Very happy with it, first sports car and first Carb car! The person I bought this from said he was installing the compressor and told me he managed to break the high pressure release vlave, said that until its fixed any drop of Freeon I put in will leak right out of there, said he had it checked and thats the issue. Comp looks fairly new but anything can with enough care. I need the valve! It should be greatly cheaper than the compressor at any rate and wanted to know if anyone had an extra one lying around!? Let me know Greg

IAGTA

Both the high pressure switch, located on the hard line that runs from the condenser to the evaporator (at least on my 1988), and the low pressure switch, located on the back of the compressor, are available at the local auto parts store. I'm replacing my compressor and needed a new low pressure switch so I purchased one at my local NAPA store today. I know Rock Auto has both listed on their site.
Good Luck!

Reid Fleming

You have these backwards.

The low pressure switch is on the accumulator.

The high pressure cut off switch is in the back of the compressor. You'll need a snap ring tool to get the old one off and the new one on. After that, they should be easy to get out.

The high pressure switch on the line that runs towards the evaporator turns your radiator fan on when the high-side pressure gets high enough to warrant turning it on.

You are correct in that these are readily available at local parts stores.

IAGTA

Reid - thanks for the correction. After I posted this information (and I'm a total rookie when it comes to these AC systems) I noticed that the factory shop manual correctly calls out the compressor mounted switch as high pressure. The online parts guides often mis-identifies this switch and that's where my confusion came from.

Another interesting issue is the color of these switches. The factory unit on my vehicle was red. This color is no longer available and was originally replaced with a R12 compatible white switch. These have now been superceeded by a R134A light blue switch. When going through my local NAPA store to get the correct replacement (I couldn't get the original switch out of my old compressor) the part number recommend on their web site and at the store is incorrect.

The correct new R134A compatible switch part number is 207097 (at least for the 1988 GTA).