GM IAC valve not working on MS3PRO

[Roofy]

Hey all, I've got an issue with my car. Using an LS1 throttle body and IAC, and I can't get it to work at all. I've checked out all the wiring, tested with a known working IAC valve, and even checked continuity from the gray plugin to the IAC valve pigtail in the engine bay. I am not getting any voltage at any of the pins on the MS3PRO. I put the IAC valve in test mode in Tunerstudio, and tried upping the stepper time from the default 1ms up to 20ms and nothing. The test mode shows the gauge sweeping from open to close, but nothing is happening at the IAC. I even took the bottom off of the MS3PRO case and checked for voltage directly at the soldering points for the IAC pins using a DVOM. (#30-33 on the gray connector) Everything else has checked out, my 5vref is good, TPS reference is good, and I even double checked the continuity of the F1 and F2 fuses. Are there any other settings to check out before I pull my hair out and scream at the moon out of frustration? Thanks for any and all help!

[Matt Cramer]

What happens if you turn the Stepper 1 and Stepper 2 outputs on in output test mode? This should give you 12V on Stepper Out 1A and 2A. Let me know what you find.