240sx A/C compressor
 

I've had my A/C belt off of my car for a while, and when I tried to put it back on the A/C doesn't work and makes a constant knocking noise that I can feel through my pedal (i think my clutch may be stuck partially engaged/disengaged) and my A/C light doesn't come on the button when it is engaged. So I think it is the clutch and am going to get a junkyard compressor today, but was wondering what could be causing the knocking noises (could it be the sliders or lubricant inside the compressor?), and if it is just the clutch then I will try changing it on the car so that I don't have to drain the system then get it recharged because it doesn't leak now and i don't want it to. But the knocking only occurs at idle, what the problem is? :vash:

John

being a mechanic, i will say there are very few vehicles, that I would consider preforming a clutch change wile the compressor was mounted.

damn, well does this sound like the just the clutch or is the compressor shot? I have no experience with A/C's

if the clutch won't engage it's usually because the a/c pressure switch is seeing too low of pressure, aka your freon leaked out. try jumpering this to rule it out. the knocking i've got no clue