AC Wiring question

[Usanumber1]

I have a 99 Suburban LT, I swapped in a 12 Valve Cummins, and kept all of the factory HVAC. When I thinned the harness, I cut the [i believe] the DK GRN low pressure wire from the hose that attaches to the hose assembly at the high and low ports. I can’t figure out where it goes after hours of scouring the internet and studying my wiring diagrams.

Any help is appreciated.

 

[AK49BWL]

If it's the sensor that sticks out from the high side (exit, left side if you're standing at the front of the truck looking at it) in the line at the compressor, that wire is the A/C request line to the PCM (C3, pin 25 on the 99 PCM), and should be dark green with a white stripe. The wire next to it should be light green coming from the HVAC control head.

 

[Usanumber1]

Negative. It’s the sensor that plugs into the hose assembly itself, it’s not attached directly to the compressor.

thank you for the response.

 

[AK49BWL]

I said, in the line at the compressor. There are only three of these switches: that one, the one in the back of the compressor, and the one at the dryer.

If your PCM/ECM doesn't have provisions for controlling the A/C, you'd need to wire all three of these switches in series with each other and connect one end of the switch series to the HVAC controller and the other end to the compressor relay. Since the PCM grounds the relay normally, you also need to change the relay triggering wires.