1998 Cavalier 2.2L A/C Problem

[buck1]

Hello to all.
I have a '98 Cavalier with an A/C problem. When the A/C is turned on, there's no cold air, the engine rpms don't increase(I don't think the compressor is engaging), and the cooling fan doesn't start running. I've checked fuses(all that I could find) and the A/C relay(checked continuity of relay coil, it's OK). I also bypassed the fan relay(jumpered across contacts) and the fan ran, so it's apparently OK. The blower works properly, all 4 speeds. Don't have a wiring diagram or could probably figure it out. If you know of a possible fix, please let me know. Thanks for any help, Buck

[KJRich]

If the coolant charge is too low, the compressor won't kick in either, so that might be one cause.

[buck1]

Thanks for the reply. Would low refrigerant pressure keep the fan from running? If so, that may be my problem. Also, if that is your black Cav., it sure looks better than mine. Have a good day and thanks again. Buck

[KJRich]

Does your fan still come on like normal to cool the engine?
I'm no tech, but the fan coming on with the a/c feature might not work unless the compressor is engaged.
Thanks for the compliment on my car.

[buck1]

The cooling fan doesn't run when A/C is turned on, which it should. The only way I've been able to run the fan is to jumper across the fan relay contacts. I think I'll look for a pressure switch on the refrigerant lines tomorrow. If I find it, I can jump it out and maybe that will tell me something. I'm outa here for tonight. Sleep tight and hope to hear from you tomorrow. Thanks, Buck

[KJRich]

Good idea. I've used the low pressure switch jumper wire trick before to check compressors on other cars. Problem is, I don't know where it is on a Cavy. Let me know how it turns out.

[buck1]

Well, I found 'a' switch but not sure what it is. It has 3 connections(3 wires coming to it) and I wouldn't know which ones to jumper. Don't want to short out the wrong thing. Anyway, when I unplugged it, the cooling fan came on. I assume it needs recharged with gas so I'm going to let a shop check it and recharge if necessary. I'll post an update if that fixes it. Thanks for your replies. Buck

[KJRich]

You're right, that sucks. The ones I jumpered in the past only had 2 prongs, so it was easy.

[rmacdear]

I too am having the same problem. The problem surfaced after I replaced the head gasket. I had not driven the car since winter, so the fan not starting was not an issue. I found wiring diagrams from AutoZone.com, and you can too. My investigation into this problem has led me to narrow it down to either the PCM ($350CDN), or the A/C pressure switch, or actually a low PS situation in the system. Anyone know how to test the 3 wire A/C presuure switch?