Hey y'all, everything on my A/C system seems to be working correctly EXCEPT the cooling. Compressor does not come on. There seems to be freon as ever time I press the filler valve, freon comes out. Is there anything in particular I should be looking at before I take to a mechanic? One question I have is, the switch located on the accumulator (I think that's what it's called), can this switch be removed without all the freon escaping? My system is still R-12. Thanks for any help.

 

What year and model? On my 86 240, the switch in my receiver/dryer will open when the pressure is too low.

 

It's a 1991 740...non turbo.

 

Does it have the climate control system, or simple *****/levers? If it has climate control, it has a self diagnostic function.
If you jump +12v to the single wire leading to the compressor clutch, you should hear it engage. If it does, you can start to look into pressure switches etc. You can briefly bypass pressure switches by jumping them with wire, but do it very briefly with the engine running to see if the A/C compressor comes on. I say to do it briefly, as you don't know if system pressure is too high or not.
If it shows an issue with pressure switch, I would have the system pressure tested, or try a second hand switch.

Regards, Andrew.

 

Yeah, you can change the presure switch without the gas escaping. First I'd check the compressor if it engages by bypassing the switch: just unplug it, and short the plug with a paper clip or similar. The compressor should kick in AND cool if everything is ok, and that would tell you that the switch is the culprit.