Making A/C operational without PCM???
 

Who can make it happen for me? I have this
http://www.lt1swap.com/pictures/fig_14.gif


But it doesn't really mean anything to me. I don't want to run a toggle switch or anything like that, I just want to turn my knob to cold and, BOOM, A/C. The vehicle is a 2007 classic silverado. Thanks

I can't profess to knowing exactly how the 2007 trucks do it, but you should be able to hook the high and low switches in series and use that feed to trigger the clutch relay. Bypass the computer completely. May throw some sort of stupid code though.

You cant without the OE PCM. The HVAC control module in the cab handles all of the interior HVAC operations then sends a class 2 request for the a/c compressor to function. A toggle switch and a relay wired inline with the pressure switchs will be the only way I'm pretty sure.

Use the toggle switch to power the coil of the OE a/c clutch relay/// Then intercept the wires to and from the switches at the pcm. Feed ground through all of the safeties and then to the other side of relay coil.

Your a.c clutch will function but there is no way around having a hidden switch to operate it.