I recently purchased a 87 240 gl model. The previous owner told me that the compressor seized up so his mechanic bypassed it with a shorter belt which is true. However when I use my hand to turn the pulley on the compressor, it turns and isn't seized, it moves but with a little hesitation. But with the belt on it I'm sure it would turn fine with some tension maybe? I'm not sure maybe the bearing in the pulley could be going bad or is their supposed to be a little hesitation? If also I have a knob for the ac inside the car not the switch. And when i turn the knob into the on position for cold air, it makes the idle go up and the car surges as if it's giving power to the compressor and it feels like it would work if the belt was attached I need help

I once had a rotary compressor seizure. It occurred when the evaporator froze up and the compressor ingested refrigerant liquid. The seizure shredded the AC belt and I had to drive on with no power steering. Afterwards I placed a new AC belt and AC has been running well since. Its been over 10k miles and it still seems ok. My AC system has an aftermarket particle filter before the expansion valve. I also like to keep the AC belt loose so maybe that helped prevent permanent damage when the seizure occurred.

Hi,

That the AC compressor's pulley - that is supposed to turn freely.

The seized part would be that round metal plate located at frontmost of the pulley - the part with one little centre bolt - known as the clutch or magnetic clutch. Try to turn/spin this clutch by hand. When a compressor is said to be seized it actually refers to seized clutch. The clutch is linked to internal compressor parts. This means the compressor is damaged. Entire compressor replacement (compressor+pulley+clutch) is the only solution.

Regards,
Amarin.

And if the clutch is good do you think a new belt for the ac compressor may make it work?

No it won't work. Although the clutch may spin a bit now as the seizing episode had come and gone a time ago but I doubt it would be silky smooth like in a healthy working compressor. Damage is already there.

Regards,
Amarin.