so i think the compressor gave out in my yukon, it was making chattering/ticking noise for about a week and just as im out of town it starts getting warm and not cooling of, noticed the chattering get really loud so just shut it off until i got home. got home and tried it again and it stalled the engine, let it cool down and tried it again and it won't even try to come on now...was pretty sure its the compressor but i stuck a pen into one of valves by the condensor and absolutely nothing came out...ideas?

 

You have a refrigerant leak and it caused your compressor to lock up. Sorry but it is time for a flush and AC system rebuild.