Ok A/C use to kick *** but all of a sudden my compressor is running erratically or should I say not running. When I first start turn on the a/c, a/c clutch engages for maybe 3 secs, shut off, does it one more time, that's it. Maybe a couple of really short engages like a half second but never starts back up. Lowside will get down to 50 psi and shut off. The really short engages is making me lean towards a bad low side pressure switch, possibly bad High side. How do I remove these switches and do I need to evacuate the system before replacing, thanks.

 

Sounds like your just Low on Freon.

 

Remove that plastic plug on it with your finger tips. There are two pieces on the side of the plastic plug that basically snap on.

Once you have that off, unscrew the low pressure cycle switch. You'll probably need an open end wrench to loosen it.

No need to evacuate the system. There is a schrader valve behind the low pressure switch. So when you remove it, it may go "pfffft" for a split second. But will stop very quickly too.....Install is the reverse. Don't overtighten the low pressure switch. The part that screws onto the accumulator will crack if overtightened.

 

Sounds like your a can low. If your running R12 this might be the time to upgrade to R134a or R152a. If your already running 134 just put in a can until you see moisture condense on the accumulator. Since your switches are 25+ years old you might want to replace them. Follow Reid's advice. If you still have R12 and don't have your own supply it will be $$$ at a shop that still caries it.

 

Might try wiggling all the connectors on the system. Mine loses connection at the high pressure cut out on the back of the compressor. Works for a while then quits, usually on the highway. I put a jumper on it for now. Usually short cycling points to low refrigerant, but the LS pressure should show this.