I'm going to write this down before I forget. I just had to relearn it again.
HOW TO GET YOUR STOCK A/C WORKING WITH THE HOLLEY
The evaporator pressure switch has two wires. The light green wire (input) comes directly from the a/c controls. The dark green (output) then goes to the factory a/c compressor control relay where it is controlled by the stock ECU. It turns the a/c on or off for certain engine conditions (WOT for example). In order to make it work without the stock ECU, take the dark green output and run it directly to the compressor clutch. The compressor clutch has two wires. The dark green, which we now have coming directly from the pressure switch, and a black ground wire.
A junk yard vehicle can supply the needed fittings as another option so you don't have to cut any stock wires. Find a female connector that plugs into the stock connector as shown in the pic (standard S10 stuff).
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grab a pigtail going to your compressor clutch (make sure you get the right style of connector, they differ), and splice the two together. One wire for clutch, the other is clutch ground that goes to the factory ground location. No need to make a new ground.
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