Testing an A/C compressor?

[Burnrate]

How do you test the clutch and coil on a compressor. I have used one out side the car that I have not installed and when I apply Ground to the case and 12 v to the black wire I get a very slight click in the compressor. and when I turn it by hand I cant feel any pressure difference. Shoud I see any Movement? Do I need to test it another way? I have seen a lot of compressors in the car with a charged system that give a very loud positive click when they engage. I have never worked on an uncharged one before.

Thanks,
Eric

[FestYboy]

clutch takes about 20A to keep it locked in place. testing is just as you described, and you should see movement at the clutch plate. try using 13.5V to apply clutch instead of 12 as you can't have the clutch engauged when the engine isn't running, you should hear a difference in volume of the click. if you don't, you either have a weak ground or weak clutch coil.

[Burnrate]

Thanks! I was using the Batt with the car off. Jumper cable test. I ll try it this afternoon. If Not Are there coil kits for the compressors? It looks easy to replace.

Eric

[FestYboy]

there may be replacement clutches out there, but just clutches are getting hard to find.

[Burnrate]

Clutch was stuck in the "in" position. My Brain was not putting together that the clutch and pulley where always turning together. I had stuck it in the car to test it some more and it broke lose when the belt started turning. Locks up fine when power is applied. What causes the two to separate? Is it like disc brakes and the rotation separates them or is there a spring? Still not separating as cleanly as I would like so it either a weak spring or just tight from setting. Going to look in the sevice manual now....

Eric

[FestYboy]

the only thing keepong it form retracting like it should would be rust or other debris on the shaft that the clutch rides on. an electromagnet locks the two together, and when it's released, you should have about .015-.020 clearance for the pully to spin freely. the pully bearing may have debris on it as well, i recomend some BP Blaster and turning the clutch on and off repeatedly untill things loosen up the way they should.