I have a 2004 f150 5.4 triton.The compressor recently decides to work when it wants. While running I pushed down on the pigtail connection into the compressor and the compressor engaged. Turned the truck off and then back on again and compressor not engaging again.i unplugged the pigtail to look for corrosion and didn't find any. Any ideas?

 

Does it work when you first start it for a bit and then stops working?

 

Check for excessive clutch gap first.

 

This ^