A/C Compressor clutch

[daveklein]

The compressor clutch on my 95 GMC 350 does not engage when I turn on the A/C.....I checked voltage going to the coil plug in and it reads 13 volts so I know the power is getting there...My question is can I replace the clutch with the unit still bolted in ?? I can turn the outside of the clutch assy so I don't think the compressor is locked up...I do seem to get some cold air out of the vents but not nearly like it should...And it takes awhile to get even a 75 degree air at the vent.....
I know you Northern guys don't worry about the A/C right now but here in FL. we use it all year.....Thanks for any help. Dave