A/C compressor not working

[Ace67]

I have a 2001 Explorer XLT 5.0 AWD. Apparently my A/C compressor is not working. Air not cold when turned to cold and defrost does not work well at all. Is there any way for me to try to diagnose/fix whatever problems might exist?

 

[my98nnj]

It could be low on refrigerent.

 

[drdoom]

It could be low on refrigerent.

Most likely is...with truck running and A/C on, pull the plug on the low pressure switch at the accumulator, and insert a jumper. Compressor should cut in.