Brendan Baker

For about a year straight, when my AC was on the engine would surge a bit but it would work. Fast forward to a week ago. I finally got interested in working on my vehicle myself and noticed that the radiator fan wasn't even on. I replaced the relay for the blower fan. Everything was fine, no issues.

Now the AC won't turn on at all. My uncle has an AC manifold gauge and verified that the system is charged to the correct levels on both the high and low end. I spun the ac compressor clutch with my hand to verify it wasn't seized. I then removed the ac relay and used a paperclip to bypass whatever sensor to verify that the clutch would engage. The clutch engaged and I took the paper clip off 3 seconds afterwards.

The radiator fan does not turn on at this point, all relays and fuses are good.

So now, I know the system is charged, the compressor still works, but I just don't know what sensor I would look at replacing. I can easily get to the high end sensor. Is there a low end? If so, where at?

Also, if it is the high end sensor I should replace, can I just twist and pull it out, or do I have to have the system vacuumed?


My engine is an 2.2L OHV SFI (LN2 Engine)
Base Cavalier

Thanks

oldchevy

There is a low pressure sensor that turns off the compressor when the freon is too low to prevent damage to the compressor. It is usually on the accumulator. You can jumper out the wires and if it turns on then the sensor is bad or the charge is low.

BW56

When i worked on mine i put the ac relay in wrong. 3 months to find the simple fix. Duh.

Brendan Baker

I ordered a pressure sensor cable. Its a s619 connector. I assume the cable is going to need to be crimped to the tps sensor cable that connects to this thing. I'll someone else connect the cable for me once I get it.

Also, the relay is good and in properly. I even tested another relay to verify this.

kevinkpk

Are you sure it's the cable, not the switch?

tech2

what year is your cav?

Most late 90"s and newer A/C compressor clutches are controlled by the pcm.

are you talking about a harness/cable for the a/c pressure sensor?

Brendan Baker

Its an 02 cavalier.

As for the PCM, I never really knew what that thing was or what it did so that wasn't really one of the things I was looking at. How would you know if its bad?

I am talking about the cable itself that plugs into the sensor. Not sure where it really runs to so I tried following the cable for a bit, but then I got tired to removing the electrical tape, so I'll try again later once I get the cable in the mail.

Brendan Baker

***Problem Solved***

I got my cables, and a crimping tool w/ butt connectors 16-14. The connector that attaches to the high end sensor on the AC was the issue. The cables were different colors but, you'd have to be stupid if you couldn't match them up with the right cable.

An s619 connector is required and costs $15 on average for the part.

Fired the car up, AC is back and it only cost me $30 w/ tool and butt connectors. If you have the tools it'll run you about $20.

I'm very happy that it was just a simple connector rather than something bigger.