Need help with an AC issue

I am trying to use a 2003 Silverado harness for a swap and I have run into a problem with the AC request signal. According to my schematics the AC request from the original silverado HVAC unit operates on serial data.
Is there any way to get the AC request to work on 12v or ground??

Of course I could bypass the PCM and just use the pressure switches to operate the clutch, but I would rather not lose the PCM's control over the AC.

Any thoughts here anybody??
Is it possible there is a way to switch that input from Serial to 12v activation, or use another pin to accomplish this somehow.
This is the last wrinkle in this swap, I would like to get it fixed.