It's on my 2006 Dually, CTD, 2wd. I replaced the AC clutch and coil in 2012 (the last time my AC stopped working). It has worked fine until last month. I ordered another clutch, coil and pulley bearing. I installed everything and the clutch isn't engaging. I shimmed properly too. I checked voltage at the plug and I'm getting 12 volts when the AC switch is off and 14 volts when it's on. This has me really confused. I also noticed that the old coil was covered in oil.

How bad is the damage?

 

Also,
I'm going on a little trip tomorrow. Can I just unplug the coil so that my AC clutch doesn't engage until after I figure out what's wrong?

Thanks,
Richard

 

Have u checked for proper service, the a/c will not engage if press is low, yes u car unplug the compressor.

 

Sounds like you have compressor seal leaking, replacement compressors come with clutch already installed.

 

With A/C ON, check the voltage at the plug with the clutch connected and report back.

 

Also try jump 12V from battery to clutch to see if it engage.

 

I had the same thing happen. You should change everything if it is a burn out. I changed the comp,cond,high side and low side refrigerant lines and orifice and the receiver.You will have to flush the evaporator also. It cost me about 500 in parts. You will also have to pull a vacuum on the system prior to charging.