Vintage Air with LS Swap - non-pcm control strategy

[NC_John]

Originally Posted by ls1nova71

What you can do is find a blue/green PCM that has IAC drivers in it, add the 12v request wire, then have the tune changed to make it work. If I remember correctly, you need to change it from serial request to analog cycling. This would allow you to control the compressor through the PCM. What it wont do though is run the electric fans, you will need the VA trinary switch for that. What is the service number on your PCM? I'm going to make a wild guess that its 12586242, but if it's 12586243 then that's the PCM you want. There are others that will work, but these are specifically 2004's.

Ahhhh... the man I was hoping to hear from!

Well, this PCM is already cracked by HPTuners and I sure don't want to buy another license and I'd really prefer to manage the on/off of the AC through the Vintage Air controls, just for simplicity.

LT1swap.com shows pin 14 as A/C Refrigerant Pressure Sensor and pin 43 as the AC compressor clutch relay control on the green harness. 43 must incorporate the logic for WOT and high RPM cutoff. I wonder how to enable that output works regardless of whether or not the PCM is actually controlling the AC compressor. How can I force the PCM to always send an AC compressor request as an output but just use it to drive the relay that goes in series with the Vintage Air compressor signal.

Might just be easier to go the external NX and Holley switch route.

Think I can see any of this through a tech II ? I don't know if HPTuners will go that in depth (and I don't personally own that software). I'll check the service number this afternoon/evening.

thanks