Don't know what's wrong with A/C?

[philjw90SHO]

The A/C in my 1990 3.0L SHO quit working sort of suddenly and I can't really figure out what's wrong. I ran the self diagnostic test on the climate control and it came back with no errors. However, I just recently popped the hood and looked at the A/C compressor and it doesn't look like its turing at ALL!! But the alternator is turning and the belt doesn't feel that loose. I am not a mechanic but could it just be that the belt is just good enough to drive the alternator but not the a/c compressor. Or could it be that the compressor seized and it is stuck. I really doubt that though because if the belt was still good then it would rub against the compressor and cause noise and smell. I just want to fix the a/c as cheaply as I can and I've told you everything that I know. Can someone please give me some advice.
Thanks

<small>[ June 27, 2002, 04:33 AM: Message edited by: philjw90SHO ]</small>

 

[projectSHO89]

Any 'cheap fix' would be the result of pure luck.

Your possibilities include: clutch/coil failure, pressure switch, CCRM (relay), compressor failure, refrigerant line failure, climate controller, and a few other I might have missed.

Try to find someone familiar with auto A/C systems nearby to give you a hands-on opinion or you'll have to take it to a shop.

Steve

 

[AutoXSHO]

I think Steve hit the nail on the head. You need to do a proper diagnostic of the system.

Where I would start is with the compressor. With the car running, the pulley must be turning or else you'd see smoke from the belt slipping on the compressor. So the compressor is likely not seized. Now, is the clutch engaging? When you turn on the AC using the climate control system does the clutch engage? If you look at the compressor with the engine off you can see that there is a part at the end of the pulley that spins independently of the pulley. This is what you look for with the motor running. If it's not pulling in, it could be for a number of reasons:

1) Freon pressure too low (triggered low pressure switch)
2) Freon pressure too high (unlikely)
3) AC clutch gap is too large
4) AC field coil is bad.

You can bypass the low pressure switch (look in the manual to find where it is) to fool the system into thinking there is adequate Freon pressure. If the compressor kicks in, you've found your problem. Find the leaks and refill with Freon.

If not, it's probably the clutch.

AC stuff is really pretty simple, but it's a bit intimidating sometimes.

John V

 

[andy1]

I just fixed my A/C on 93 SHO . Just stopped working. The problem was the compressor was getting no power. The connector came off. Its the only wire going to the compressor. You can barely see it but check it out.