Right it won't supply 9v. You probably don't want it supplying the power anyway, may have noise on that too. As for the IAC stuff, I run smoothest once I disconnect the jeep tb IAC after I let it adjust once. I remember XtremeRS saying his stock IAC moved out once he hit boost, so it would loose it's idle.

The best method would either be seeing how to get the MS to control the jeep IAC since I've heard it's been done.