Thread: A/C button no longer turns on compressor. Ideas?

My A/C didn't work today when I turned it on. Frustrating, given that it's warm and muggy right now.

I checked the A/C fuse on the driver's side inside the car. Fine.
I checked the A/C relay that sits in the engine bay. Fine as well.

What would cause it to randomly stop working?

Not what I need right now.

Please give me some diag suggestions.

either the a/c system has a leak and the system is empty or close to it or one of your pressure switches is bad. I cant remember if there is both a high pressure and low pressure switch on our systems. The high pressure switch would be on the high side line and the low on the low.

If the system is low in pressure it will not allow the compressor to kick on due to the damage it could cause to the compressor.

It could be your compressor itself. Check to see if your getting 12v to the compressor when you have the a/c switched on. If so then your compressor clutch is bad. If you are not then its probably due to the system being low in pressure. Check for leaks and fix them and refill using a proper machine.

oh and the way you can test the pressure switch is to unplug the connector and jump the wires, if the compressor kicks on dont hold it for more than a second or so.

It might help if I actually knew what the pressure switches looked like...

One line has a red cap on it, the other line has a blue cap. Which ones which?

What does a pressure switch look like?

Thanks.

lol those are the service ports. the switches have a two prong electrical connector on them. I cant recal where they are located at. one is a high pressure and one is a low pressure. Unless i had the system to look at i cant tell you exactly where they are located.

You kinda have to know how they operate and have the knowledge of how the system works. Good luck though.

did the compressor worked?

do the jump thing in the compressor, if it work u maybe have the a/c relay broken.

i Just got my car out of the shop for that.

the only 'switch' I can see is on top of the condenser dryer. Is it possible there is only one switch, to detect both high and low pressure?

Lemme know what you find out. I have the same problem.

thats probably the right one, start with that one and jump it, again if the compressor comes on then its either the switch or your system charge is low and needs to be checked.

Well, I'm about to try this.

Last night though, I removed the blue cap for the low pressure line, pressed on the valve with a small screwdriver for just a moment to see if it had pressure, and it only had a small amount of pressure. I pressed it again after that, and no pressure was released.

Automatically I'm just assuming that this means my low pressure line was very low, and now it is completely empty.