My Air has not worked in over a year. When it was going bad the clutch would spin on engine start up for about a min. and then shut off and not start again until sometimes the next day. Recently I took the truck to a shop and they recharged the system and it now has the proper charge in it. The clutch does not turn at all on its own. I can turn the clutch (3 pronged inside portion) by hand. I have checked at the power plug in the compressor and it has 13.8V when the air is turned on and the prongs that it connects to have continuity between them
indicating that the coil should be good.
What is left to be wrong?
98 f150 4.6 auto.

 

You can adjust the clutch. sometimes the gap is too big and it won't engage properly. try pushing on the clutch plate with a wooden dowel and see if it will engage then. The nut in the center of the clutch can be removed, you pull the disk off and behind the disk there are washers. when you install a clutch new the clutch comes with several washers of diffrent thicknesses. If it is indeed out of adjustment try putting fewer or thinner washer(s) on.

 

If the clutch is bad, you can have it replaced pretty easily. My buddy with a 97 4.6 just had his replaced for 175 bucks