Yes there is a AC clutch fuse located in the engine compartment. It is a 10 amp fuse' check your manual it will tell the location. If that fuse is blown and continues to blow fuses the have the coil in the compressor checked, also the pressure switch.
It is possible to replace the air conditioner clutch without replacing the entire compressor if you can find somewhere that sells just the clutch assembly and can get the appropriate tool to remove the pulley to get to the clutch. Try buying a repair manual and looking in there.
Are you replacing a whole clutch or just the clutch plates?
If the clutch was not disengaging I would say the clutch master is empty of hydraulic fluid, this would be a result of a leak in the master or the slave cylinder. If the clutch is not engaging I would suspect the clutch disc has shredded in which case the clucth assembly would have to be replaced.
your clutch may not be fully engaging
Depends on what exactly is wrong with it :) Unless it is about simply replacing or adjusting the clutch cable, replacing the clutch involves removing transmission out, which means taking the axles out etc.
Yes, most newer cars have a clutch safety switch that prevents the starter from engaging if the clutch isn't depressed.
Clutch engaging/charged- (freon) I would check those things next. If you are low R12, you might have a bad o ring somewhere.
Difficulty engaging gears and noise when actually engaging
At least the slave cylinder. The clutch master cylinder can be replaced at any time.
My car is going through the same issue with the A/C. You CAN replace the compressor clutch without replacing the compressor, but the caveat is that you can't tell if the compressor is any good without a clutch. So basically you are gambling that the compressor will still be good by only replacing the clutch. Hope this helps!
There is one cause for this. If the throttle body is moved or adjusted in any way this will cause the judder when engaging gears.
Technically, it never touches the flywheel - the clutch disc does. You can stop the flywheel (stall-out the engine) by engaging the clutch in gear with the brakes firmly applied.