Not getting power to the AC
 

Are there any particularly common areas to look for the fix. The relay is fine. the compressor will kick in if jumped, but not otherwise.

When you say "jumped" do you mean when you run 12V directly to the clutch? Or is it when you "jump" the pressure cut off switch?

I had the same problem with my 951, if there is insuficient gas in the
system it will not activate the compressor. its easy for me to check as
I am an aircond tech. you may have to take it to a local aircond service
tech.as in my case it may only require a top up, but i converted it from r12 to an alternitave , works well.
Red 951 , chiped, very fast,showroom condition