AC pressure switch location? Compressor wont kick on

[spacerabbit69]

I have a 2007 grand prix gxp. My am not getting any cold air. My compressor will kick on every now and then, or at least it did. Yesterday it would get cold for about a min and then hot again. Today it didn't turn on at all. I think the compressor is bad, but my neighbor said he doesn't because when it was turning on it was working good, blowing really cold, and didn't make any noises. He said he thinks the pressure switch may be bad and or that we need to jumper the switch to get the compressor to turn on and check the freon. I don't know where this switch is. It is very hot in Florida right now. I'm about ready to take it to the shop, but really don't want to spend the money if I can fix it myself.
Thanks in advance!!!

[BillBoost37]

You can put a set of gauges on it and find out what the pressures are to see if you are low. If you are low..that may explain the cycling.

Jumpering, will override the pressure switch ....which is a safety on the system building too much pressure etc.

[selliott]

^this

[spacerabbit69]

What if the compressor won't kick on. It hasn't kicked on since the day before yesterday. I put the gauge on and it's reading in the red, too high. My neighbor said it will do that if the compressor doesn't kick on. The car needs to be on with the a.c. on as well when hooking up the gauge correct?

[BillBoost37]

First off...there's two gauges when done properly.

High side
Low Side

Yes things will look differently when the compressor is on vs off. However the high pressure switch is there for a purpose. I believed you weren't using two gauges and knowledgeable on AC. This is why I posted the suggestion of two gauges before jumping the compressor.

If pressure/freon is low, a compressor won't kick on, if it's too high.. the compressor may not kick on. That switch can be bad...but it's more often helping you stay safe.

[spacerabbit69]

I Only have one gauge and no Knowledge on ac. Where is the second pressure port? I have it on the one on the top by the firewall. I'm assuming that Is the low pressure side? And I don't know where the switch is to even test it or jump it. I'll buy a second gauge and try that, I need to figure out where it Is at. And what I should be noticing when I do hook both gauges up.

[Scottydoggs]

most GM cars seem to have a green wire to the ac compressor plug, and another wire in the plug. this green wire if you can trace it back should lead to the hi pressure switch, if theres no Freon the switch wont power the compressor.

ive powered the green wire to see if the compressor would turn on in the past. just to make sure it still worked.

[spacerabbit69]

Thanks, I'll try to trace it when I get off work

[Scottydoggs]

theres always the chance the hi pressure switch is bad too. as its what tells the compressor to turn on.

[BillBoost37]

Wouldn't it just be easier to tell him it's next to the trans on the line going to the accumulator?

I didn't tell him... because I don't want to feel responsible in any way when he blows himself up.

[spacerabbit69]

I appreciate the help, advice, and concern. I don't want to blow myself up. What would I be doing to even cause something like that to happen? I'm just trying to troubleshoot what is wrong with the a.c.

[Scottydoggs]

jumping power to the green wire is a test, just to see if it runs. you dont want to keep it like that. you see it run, you take the power back off asap.

sadly sometimes a/c systems are best left to the pros. and i know they like to charge out the ass. but they deal with it everyday and have the right tools and equipment to get to the root of the problem.

and they wont waste your r-120 whatever as they will suck it out and tank it, then reuse it after they fix the system. where if you open the system your just dumping it into the air then have to buy new. unless you have these cool tools they have.