More for lights, running my high power ham radio gear, and winching actually. I run a ready welder instead of the on board welder (it is 24v for most jobs but that just requires swapping the cables on my dual setup and is much more flexible).
That would work, I have toyed with the idea of something like that, trying to fool it into thinking the AC was on and stepping up the idle with the IAC, or finding an easily controlable IAC off another vehicle and rigging it up as a "controlled vacum leak" that will do the same thing as the stock IAC.
I am running toward the latter two, I need to play with vacum hoses and see what will work. That way I can do it from the cab.