A/C compressor not turning on

[Jetfumes]

I have a 2000 yukon XL with front and rear ac. I've checked all fuses which are good. I'm trying to the AC with r-134a which is low, but can't get the compressor to kick in now. I've trying jumping the wires to get it to kick in but it's only temporary and turn back off.

What am I missing??? is there a way to wire the compressor directly or how can I make sure not a compressor issue now?

 

[mizzouguy]

If you have supplied power directly to the compressor clutch and it kicks back out while you have the power supplied, then the clutch is bad...if its good it will continue to run until it either grenades from lack of lubricant or loses the 12v source. If it has low enough pressure to where the compressor low side pressure switch is not operating, and thus not allowing your clutch a 12v source, then you can't just fill it with r134 and expect it to work for very long. Once enough r134 trickles in from your aerosol can you are filling from, the clutch will start kicking on for short bursts, each time it will stay on a little longer until it gets full enough to run continuously. It's at best a bandaid to help you pinpoint the leak. There is a leak, and your system has a bunch of air in it. You will need to fix the leak, vacuum it down, and refill by weight.
If I'm not following you then let me know.