How did you integrate the AC request circuit from the Merc to the GM compressor? Is it a +12 signal from the dashboard harness? Are you running either a hi and low pressure switch or perhaps a single trinary switch? What do you use to cycle the electric fans for when you request AC? I ask because I'm putting an LS in my 1992 Merc 500SL. I also am helping a friend put a Chevy engine in a 1981 Ford which also uses vacuum operated HVAC doors for vents and a very basic AC request line.
