AC on idle issues

[Davidf]

Originally Posted by 87chevy.com

what do you mean, it has its own? the vintage air just gives 12v to compressor yes, is that what the facotry GM ecu needs? then send that 12v to the ecu and wire the a/c circuit like factory.... just that easy

Yes, the factory ECU takes the 12v compressor clutch signal directly. So, you can simply tap off the Vintage Air compressor wire and send directly to the ECU "A/C Request" input.

Or, you can reroute the Vintage Air compressor wire FROM the compressor and straight into the ECU "A/C Request" input. But, then you have to use the a/c control (output) from the ECU to power a relay which sends 12v to the compressor. The ECU a/c output is a ground reference signal (used to ground the control input of the relay).

Simple. I believe ECU "A/C Request" input went away when a/c control function became part of the control/bus network...maybe 2002 or later.