Ac problem

[Walk96]

I have a 99 Tahoe with rear air that I've recently replaced the compressor, accumulator,oirfice and expansion valve, front/rear evaporator ,cycling and refrigerant switch even a new control panel, with proper oil, new o rings pulled vaccum it held so I tried to charge the system and only could get a half a can to go in the system I tried to jump the plug off the cycling switch and the clutch didn't engage, if it matters when I jump the plug the truck idles up and when I remove the wire the idle goes back to normal checked all fuses under the hood and inside at the fuse box along with a new relay......What am I missing

 

[SunlitComet]

was the vacuum still in the system when the charging started?

 

[Walk96]

Yea I guess so maybe thats why when I was putting the caps back on the high and low ports the high side port was sucking my finger down over the hole so I suppose to let the vaccum off or something?

 

[SunlitComet]

sounds like you did and it sounds like it did because a valve core is stuck open. another problem to fix before redoing the vacuum and charging.

 

[Walk96]

Ok so replace both valve cores and the pull vaccum correct? Then what after