The belt broke on my AC (87 GT). I don't know whether the the belt just broke from age or because the compressor seized. It's an original compressor and has always been noisy even after converted to 134a but has always worked just great. I was driving and lost AC suddenly and discovered the broken belt. The clutch free wheels fine so I know that's not the problem but is there an easy check for a seized compressor without the belt?

If you turn your compressor pulley by hand, you'll notice a metal plate on the end that does not turn. Try turning that plate, and if you can't, it's seized. More likely, though, the belt just broke.
Edit: The stock belt is too thin. Use a wider belt.

[This message has been edited by TopNotch (edited 07-10-2011).]

How much resistance should I expect if it is OK?

Or another thought, if I just turned the car on (but not start it) with the air selected, would I be able to turn the pulley with the clutch engaged if the compressor is OK?

[This message has been edited by YellowArtero (edited 07-10-2011).]

I don't think the clutch will enguage unless the engine is running? You should be able to turn the plate by hand, it will have some resistance but should turn by hand. Just push your palm against it with pressure and turn it with your palm.

The ECM disengages the compressor if engine RPM's fall below a certain value. So it certainly won't engage if the engine isn't running.

I got underneath and pulled pieces of the old belt from around the clutch and tried to turn the end plate. It's stiff but I was able to turn it by hand so hopefully IT LIVES TO COOL AGAIN!

Thanks

Cool yours still spins, busted my belt after 3 months on my new compressor it's seized good, smoked a new belt right off he bat. I'm now trying to get it turned in for warranty. Luckily i replaced the orifice tube, accumulator, and flushed the system per the terms of the warrenty. Paying $230 for another another compressor and then ofr the other parts would just piss my wife off.

You need A/C in AZ you could just die form the heat.

quote Originally posted by Tankrat72: Cool yours still spins, busted my belt after 3 months on my new compressor it's seized good, smoked a new belt right off he bat. I'm now trying to get it turned in for warranty.

Did you put in 4 oz. of the appropriate oil into the compressor before installing it? That's what the seller's going to ask when you try to get a warranty replacement.

yeap emptied out the oil and added ester and added it to the accumulator and evap as well.