AC high pressure switch

[Griscom_06]

First off I'm new to this forum and I've been doing a lot of searching can't seem to come across anybody else who has the same issue I have. Anyhow I have a 2006 Silverado 2500hd 6.0 motor just got the truck. Ac compressor will not turn on. Here's what I've done

1 all fuses and relays good

2 checked pressure on system and it's at 22 lbs which I know is low

3 tried putting a wire in the high and low pressure switch to force the compressor on( nothing happens)

I have yet to try to run power straight to the compressor but here's my main issue. From my understanding there is gonna be 1 low pressure sensor. And 1 high pressure sensor. Right or wrong?

So I have 2 plugs coming out of the same wiring harness at the top and I have no idea what the one that's not plygged in goes too. It's the one with the blue back on it. Does anybody have any suggestions as to what I can do to recharge the system without the compressor running? Maybe that would tell the sensors it has good pressure and will in turn run? Thanks I'm advance

[Formulabruce]

Low press switch can cause this, and shorting the terminal doesnt drop a ground. May have bad clutch, but try the windshield DEFROSTER, and see if the compressor cycles as is should when defrosting ( yes A/C is working during winter) .