Air conditioner signal integration

[GasGuzzler]

After looking at the schematic I'd say you should control it like the truck was designed and not with the 2004 PCM since this system requires a ClassII request from the HVAC controls to the PCM then the PCM grounds the compressor relay. The only downfall is idle with and without the AC on. This is something we're dealing with on RedHeartbeat's truck too although his has a more simple OS.

[93blackbeast]

Thanks GG. That's how I have it working now, using the controls that came off of the 1993 to signal the AC clutch to engage.

I was just wondering if there was a way I could use that 12v signal that i send to the clutch to maybe go through a resistor and then tap into a PCM wire that would let the PCM know that the AC is "ON". That way, it could adjust the idle and such as if it were controlling the AC. I still want to control the AC through the trucks controlls, but just like you said, fake the system out.

Does that sound like that would work at all?