I am using a PSI harness with programmed 411 pcm... I was looking over the pinouts on the original pcm and noticed the AC system controls run thru the old pcm. I have removed it and plan to mount my new pcm in it's place..... How do I keep the AC system functional,,, I am re using my original compressor on my new 5.3 so everything else in the AC system is still in it's original layout.........


Also, which wire under the hood is a good source for 12 IGN/Crank/Run