A/C Electrical Issues (I think....)

mn12sc35th

Registered User
Ok, my A/C hasn't worked for a couple years now. Well, I hadn't really tried it in a long time, because I had a cooling problem and it would overheat. The cooling problem has been fixed since then, and I decided to tackle the A/C.

I check the pressure on it to find it a little low. I filled it back to normal. Now if I test the pressure switch, I get a closed circuit, and the plug for it is supplying power. I test the compressor clutch plug and find both the ground is good, and it's supplying power. This leaves the clutch/compressor itself....

So can the clutch itself just go bad? If so what can I do about this?
 
What did you check the pressure with and what is normal for pressure? You have to have the compressor running to check the A/C pressures. Yes the clutch can go bad. But I would suggest getting someone that is a qualified A/C tech. to check it out.
 
airgap

What is the airgap between the clutch and the pulley? Should be around .020 inch. IF it is much over .030, tha airgap needs adjusted.
 
For pressure, I had one of those refill kits with a gauge(I dont have the spare cash for a manifold set right now :p). Normal is supposed to be 25-45PSI on the low side. It apparently was in range because the pressure switch was closed.

I'll have to check the gap... never heard of that.

As for paying someone, I'll yank the sucker off before I spend that much on it :p I've gone several years without the A/C anyway, I can manage :)
 
25 - 45 when the compressor is engaged. You can bring it to me and I could check it out for you.The compressor gap is not going to help if there is not enough freon in it to begin with.
 
a/c electrical

If you have power and ground at the compressor connecter you dont have a pressure problem. Get an ohmmeter and Check for continuity across the compressor clutch itself no continuity= bad clutch continuity from either terminal to ground= bad clutch. I am sure you will find the problem. Hope this helps:)
 
Yeah, I forgot that little compressor running detail.... At least I didn't listen to the kit when it said to dump a whole bottle in there if the compressor isn't running. :p But when the pressure switch came up closed, I pretty much ruled that out.

As for the clutch, I get about 3ohms between the clutch terminals, and nothing between either terminal and ground.... The plug on it's a little lose, but I can play with it all I want and nothing. The shop manual says to jump power across the clutch, so I'll have to try that next.
 
Are you checking power and ground with an dvom or a test light? A dvom may show them good even though you don't have enough current carrying capacity to fire the clutch. Get a good heavy bulbed test light and recheck. One lead on each of the clutch's terminals.
Does the clutch have a good magnetic pull with the ac 'on'?
 
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