Hello,

Newbie here, I am posting about my girlfriend's 97 Cavalier with the 2.2 and a 5 speed. Her A/C doesn't work; the compressor isn't spinning. I'm assuming it's because she's low on freon. I read the sticky but still have some questions.

Can I check the pressure of the system myself with one of those DIY kits, or should a professional gauge set be used?

Is there any way I can override the pressure switches to get the compressor to spin, just to verify it's functional?

From what I've read she's got the variable speed compressor, which should be always working unless the system's freon pressure is too low or high. I've used DIY kits on older systems, but with them I had to jump the pins on the pressure switch to engage the compressor and suck the freon in. Is that what I'd have to do on this (and if so, how?), or is the 134a under enough pressure in the can to make the system start to work?

Any and all advice is greatly appreciated!

Justin

You could apply B+ to the comprssor see if it spins.

Your car doesnt have freon, it has 134A.

If it is to low on 134A the compressor wont turn on.




- 2004 Cavalier - 124k, owned since new

Thanks for the reply, and sorry for the nomenclature mis-use. Is 'refrigerant' ok?

I'm assuming there is a plug I have to remove to manually apply 12 volts to the compressor? Do I need to run a ground wire too?

Regards,

Justin

There's a couple of ways to do that. Either run a +12 and a ground from the battery to the plug on the compressor to manually turn it on. Or you can jumper the low pressure switch near the dryer with a paperclip to turn it on. When i charge one, i jumper that low pressure switch and stick 2 cans of 134a
in. Usually that works fine, sometimes if it's really low 3 cans. I used to not use guages at all, but i ran
upon a set cheap and they are nice to see what kind of pressure the compressor puts up but not required.
Don't trust the cheapie guage on a can or the $30 "charging" kit dials they just are not accurate. My dad tried that and he believed his when he put it on as it registered 80 LBS. I put mine on and it had 15 lbs. I don't think you would hurt it by stuffing a couple of cans in it. When the pressure gets higher than 25 lbs or so the low pressure switch will allow the compressor to run. It will run a few seconds, then kick off. But after a few of those cycles it will start to stay on longer and longer and will stay on toward the end of the second or third can - unless it starts leaking out.
Don

Thanks for the input guys.

I got a chance to play with it tonight, as expected it was just low on refrigerant. I only put one can in and the compressor kicked right on, got cool at a decent rate so that's how I'll leave it.

Justin