AC compressor not kicking on

[Defiant]

My AC compressor won't engage so I have non functioning AC for the moment.

Heres what I checked:

-Physically turning the clutch by hand to make sure it isn't locked up; it wasn't.
-Checked low side pressure. It was actually over 160psi so I bled some out now it's at about 40psi
-Jumped the low pressure switch and it still didn't kick on. It just changed the idle the same way it does when I turn the AC knob inside the car.
-Verified that the 15A fuse under the driver side compartment isn't blown; it wasn't.

I have not jumped the high pressure switch nor have I tested the psi on that side. I also haven't checked the relay or ccrm I think it's called.

Can an I get any advice here? Is there anything else I should check or is that basically all of it? Also of the list of items I haven't tested yet, which one seems most likely the fault?

 

[lwarrior1016]

My AC compressor won't engage so I have non functioning AC for the moment.

Heres what I checked:

-Physically turning the clutch by hand to make sure it isn't locked up; it wasn't.
-Checked low side pressure. It was actually over 160psi so I bled some out now it's at about 40psi
-Jumped the low pressure switch and it still didn't kick on. It just changed the idle the same way it does when I turn the AC knob inside the car.
-Verified that the 15A fuse under the driver side compartment isn't blown; it wasn't.

I have not jumped the high pressure switch nor have I tested the psi on that side. I also haven't checked the relay or ccrm I think it's called.

Can an I get any advice here? Is there anything else I should check or is that basically all of it? Also of the list of items I haven't tested yet, which one seems most likely the fault?

I hate to say it but you messed up. Now the system needs a charge. With the a/c off (compressor not turning), the high and low side will equalize so now you let too much out of the system. Do you have a set of manifold gauges? Turn the car on and jump the connector for the low pressure switch, the clutch should engage, if it doesnt then I would check for power and ground at the a/c compressor connector with the low side jumped. Do you have a set of feeler gauges to check the air gap on the compressor clutch?

 

[Defiant]

I hate to say it but you messed up. Now the system needs a charge. With the a/c off (compressor not turning), the high and low side will equalize so now you let too much out of the system. Do you have a set of manifold gauges? Turn the car on and jump the connector for the low pressure switch, the clutch should engage, if it doesnt then I would check for power and ground at the a/c compressor connector with the low side jumped. Do you have a set of feeler gauges to check the air gap on the compressor clutch?

wait really? I thought low side should be 40psi and high side 150ish. I do have a brand new can of refrigerant so I'm not too worried. Just when I saw how high the gauge was I thought someone overfilled it. I don't have manifold gauges. I did jump that connector and it did not engage the clutch. So then I should check the compressor wiring with the volt meter? I'm not sure what air gap you're talking about.

 

[lwarrior1016]

wait really? I thought low side should be 40psi and high side 150ish. I do have a brand new can of refrigerant so I'm not too worried. Just when I saw how high the gauge was I thought someone overfilled it. I don't have manifold gauges. I did jump that connector and it did not engage the clutch. So then I should check the compressor wiring with the volt meter? I'm not sure what air gap you're talking about.

Low and high side equalize until the compressor turns on. That's why you need manifold gauges to monitor high and low side. Try shooting that can you have in there and see if the compressor kicks on. I would jump the low side switch and get a multimeter, check the compressor connector. Just check across it for voltage. One side is hot, one is ground. The air gap is the amount of space between the clutch surfaces on the front of the compressor. The part that normally moves inward to engage the compressor has to be a certain distance from the magnet to be able to engage. You can also jump the low switch and tap the compressor with a hammer to see if the clutch engages.

 

[lutter94]

I feel like the best place to start is to check for 12V at the compressor wiring. If you don't have it, send 12V there yourself, see if it kicks in. That would let you verify pressures then focus on wiring. If thats truly the issue.