The most common problem on these trucks will be a bad pressure switch along with a bad pressure switch pigtail.........
BAD clutch slave cylinder, wore out clutch and pressure plate.
The clutch pedal.
Well, the question is a bit vague. Is the flywheel to the compressor clutch turning? Does the compressor clutch engage? What exactly is it doing? There are several possibilities here.. a bad low pressure sensor, a seized bearing in the compressor, an overcharged refrigeration system.. kinda difficult to narrow it down without knowing specific symptoms.
An air conditioner clutch will not engage without voltage. If it doesn't engage, the compressor will not turn.
If the clutch won't engage, the clutch disc or pressure plate has probably broke apart. If the clutch won't disengage, the clutch hydraulic fluid reservoir is empty because of a leak in the system.
Is to disengage and engage
bad clutch cable, or not enough oil on the clutch plates.
If it's getting juice, a problem with the clutch. Test for current & if won't engage & getting current, you need a new one.
you need to bleed your clutch fluid
it might not have any hydrolic fluid in the clutch master cylinder to engage the cluth or your clutch might me shot and just won't engage at all meaning you need a new one (was there a smell in the car right before you couldn't use clutch? that might of been the clutch burning up). don't quote me on all that I'm just telling you what you can check.
check the clutch fluid or maybe you need to purgue
thats the relay to engage the a/c compressor clutch