intermittent a/c problem - SOLVED

[arth33]

Hi there,

Just thought I'd share my problem/solution in case it helps anyone else with intermittent air conditioning.

I was having a problem with my a/c system either working or blowing hot air. The engine revs consistently went up when the air-conditioning was activated suggesting that the switch and relay was okay.

When I started poking around, the pressures seemed pretty good (within the range of acceptable anyway - I added a tiny by of refrigerant to the system to bring the low side up). But the most obvious thing was that the clutch (in front of the compressor) would engage when the system worked, but wouldn't when the system failed. I then confirmed that the relay/pressure switch was working by checking that the clutch was getting power (simple light probe). Because it was, I could rule those out. The clutch turned freely and the pulley/belt looked fine. I then sent power directly from the battery to the clutch to see if it would engage. It wouldn't engage which made me think that I'd need a new a/c clutch and maybe compressor. But -- and here's the important thing -- I could feel the electromagnet in the clutch turn on and off. My steel screwdriver would be pulled to the clutch whenever I gave it power. I was worried that the clutch magnet coil had shorted or something like that, but if the magnet fired up, it should just be a physical blockage. To solve the problem, I used a screwdriver to push the clutch in and out (the travel is about a 1 mm to 1.5 mm). I repeated this to all sides of the clutch to ensure that it moved as freely as possible. I then used compressed air to blow out dust from the inside of the clutch and sprayed a little oil in there to keep things lubed up.

In the end it worked fine and I now have a reliable a/c system and it didn't cost me anything. Hope this is helpful to someone out there.

Jeff

[OCRentAPopo]

I'm having the same problem in my '97. How'd you send power directly to the a/c clutch?

[1 Lucky Texan]

did you see any debris come out?

[CNY_Dave]

Don't have time to search myself, there is a thread on here that mentions this and says you can take the clutch apart and remove a / some shims to adjust for wear.

Of course if cleaning it works, that's much easier to try first.

[arth33]

Originally Posted by OCRentAPopo

I'm having the same problem in my '97. How'd you send power directly to the a/c clutch?

I used a pair of alligator clips and went straight from the battery to the female end of the plug. If you tap the battery terminal a few times, you'll see some sparks fly. That way you'll know that you've got a connection on the inside of the plug.

Originally Posted by 1 Lucky Texan

did you see any debris come out?

Nothing too substantial, but plenty of dust. I think the bulk of it was just built up on the inside of the clutch and was displaced when I pushed the clutch plate in and out with the screwdriver. The air was just to remove most of the stuff that was kicked loose from that.

Originally Posted by CNY_Dave

Don't have time to search myself, there is a thread on here that mentions this and says you can take the clutch apart and remove a / some shims to adjust for wear.

Of course if cleaning it works, that's much easier to try first.

Thanks for the suggestion. I'll search that out. For now it's working, but if I run into trouble again, I'll look into the shims. That certainly sounds like a better / longer-term solution to the problem.