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AC clutch not engaging 911 It's HOT in Texas!

Long story short-My AC pulleys bearing froze up and broke the belt. I replaced the pulley and clutch, checked fuses and relays, all good. The clutch still wouldn’t engage.I bought some AC 134A and put half a can and its still not engaging. Any idea what’s next? How do I get that clutch to engage? 2002 Chevy Cavalier 2.2 Ecotec engine

TOO many maybes here. get thee to an a/c shop. this is no longer a d.i.y. job

Here’s the wiring diagram for the compressor clutch.



Don’t take this the wrong way, please

It sounds as if your AC compressor catastrophically let go, shooting metal debris into the entire ac system. Which would mean that throwing a pulley and clutch at it is wasted money

As far as those cans go, do you even know how to use them?

You can’t suck in the refrigerant through the low side UNLESS the system is under a vacuum or the engine is idling AND the ac compressor is already engaged

I suspect neither of those was the case

I agree this is almost certainly not something you’ll be able to resolve on your own, in your driveway

Db4690, ur prolly right. I just did what several people and the auto guys suggested. Some people told me that by putting the freon in, it may kick on the clutch. So I figured if the compressor is shot, I have nothing to lose but $30
Someone on YouTube said the pressure switch may be the issue as well. However, not sure I wanna waste anymore money. Just seems like auto repair shops are a bunch of scammers(as seen on Dateline and 20/20) just taking advantage of people who don’t know anything about cars. So I always attempt to do things myself first. But, looks like I have no choice this time.
Thanks for everyone’s help

@TheKennyP - I don 't have the exact count but there are several screen names that appear here on a regular basis that actually own and operate auto repair shops. As a whole they give good advice considering the vague information posted. Using the term "bunch of scammers " might not have been a good idea.

I wouldn’t put too much into what you see on Dateline or 20/20.
The job of those show is to create controversy. It’s at least possible they went to 19 different shops before finding a crooked one and the last one is the one that gets the bad press.

Those old enough may remember those shows have created a lot of BS controversy in the past.
That includes Dateline’s staged pickup explosion and the Food Lion controversy.

Some may also remember that 20/20 has also ripped military equipment in the past as being too high tech, trouble prone, broken down all the time, and seldom ever combat ready. That includes the Bradley, the M-1 Abrams tank, and the F-15 Eagle. I’d say 20/20 was dead wrong on all of them.

That being said, the wiring diagram provided by Tester is bone simple and it should not be difficult to sort out what’s what with that diagram.

Ok Volvo V70, ur absolutely right. I shouldn’t say that. I know there are good Auto mechanics out there. I shouldn’t be so cynical. I will say, I myself had had some bad experiences in my 48 years on the planet. I shouldn’t group all mechanics in that group. I have to say tho, it’s hard to find a good mechanic these days.
So to all mechanics here, My apologies to y’all!

And Ok4450, U may also be right. I agree on a lot of what ur saying. I don’t recall all that u spoke of but I’ll keep in mind all you said. Appreciate it

Just curious but are you absolutely certain the clutch bearing seized and not the compressor itself? I assume you’re correct on this; just wondering.

If the assumption is made that the refrigerant level is low, sometimes one has to jump a pressure switch or compressor connector until enough refrigerant is in the system to cause the clutch to engage.
In this case, if the dark green/white lead from the compressor relay is grounded the clutch should kick in.

If you continue to fool around with this I would suggest that you wear gloves and safety goggles.
Refrigerant released into the atmosphere can cause frostbite or permanent blindness in 2 seconds.
I’m fairly proficient with A/C so to speak and during a moment of frustration with someone’s home central A/C unit some years ago I got a bit careless and took a small refrigerant blast to the tip of my right index finger. It hurt like hxxx, hurt for a month afterwards, and the fingertip is still somewhat dead as of today.

I’ve seen WAY too many guys believe that “only” the bearing and pulley are bad, and spend a lot of time and money on those parts, only to discover that the compressor itself ate . . . in a bad way

And even if the compressor itself was replaced, unless you do a proper flush, it might not survive long

to be honest no. However, what happened was the fairly new belt snapped. So I wasn’t sure what caused it so I turned the motor and it moved. Turned all other pulleys and the AC one wouldn’t move. At all. when I removed it, it was all rusted and half the bearings were missing. SSo I replaced it, along with the clutch and thought since I put all new pulley and clutch. That it would work fine. But nope. I will say this tho, b4 all this happened the AC had quit blowing cold air about 3 months earlier. Guess I was just hoping.

I tried putting a whole can of refrigerant in and it still didn’t work. Wishful thinking.

What is all this about a “pressure switch” I keep hearing?

Thanks guys for all the good advice

If you look at the diagram provided, find the relay between the fuse and the clutch coil. Pull that relay and note the terminals of the contacts. There are four terminals, two for the coil and two for the contacts. With the engine off but the key in the run position, use a piece of wire to short out the terminals on the relay socket (A22-B20) for the contacts and see if the clutch coil pulls the clutch in. You should hear a click sound and see the front of the clutch move.

If that works, then the issue is elsewhere. You could repeat the test above with the engine running but that could lead to further damage so I would not recommend that you do that.

But if you remove the belt and repeat the test with the engine off and the clutch engages, then you can try to turn the compressor by hand just to see if it will turn. I’ve never done this myself so I don’t know how much resistance to turning a working compressor offers, maybe someone else here has.

If the first test fails, then use a voltmeter to check for 12V at A22. If you have voltage at this terminal, then switch the ignition to off and the meter to resistance and check for resistance between B20 and ground. If that is open, then the clutch coil is bad or the clutch coil is not grounded.

If the first test is good, check for 12V at B22.

Test the pressure switch by unplugging it and measuring the resistance between the terminals. AC+BC=AB and BC should be much less than AC. If the switch checks good, then you have to look at all the wiring between the switch and the PCM.

Edit: My bet, you didn’t hook up the ground wire for the clutch coil.

Another problem might be that air gap between the clutch plate and the compressor pulley is excessive. And the magnetic coil can’t pull the clutch plate against the pulley.

The new compressor clutch should have come with shims to adjust the air gap.


I’m guessing that if you do manage to get the clutch to engage, you will lose another belt. A seized clutch bearing won’t cause this but a seized compressor bearing will.

I think ur freon can is emptying cuz there is a leak somewhere that is letting all the freon out. U cannot add a whole can of freon into a closed system where the compressor is not running. Unless u have already drawn a vacuum which u certainly have not done. U are pouring water into a bucket with a hole in the bottom. Goes in fine, won’t stay in though

Cavell, would it puddle under the car f it were leaking out? I haven’t seen anything. And have been looking

No puddle except maybe a little oil. R134a, like all similar refrigerants, turns into its gaseous state when released into the atmosphere.