There is a control wire that comes from the ECU (black wire with a blue trace) it provides a pulsed ground signal that controls the IAC. With an oscilloscope you could watch the signal, but it is not something a meter or test light will show.
That junction you found at the dash is the one I mentioned above, it feeds power to the IAC, EVAP, Injector feed, and the main injector relay. You mentioned earlier that you had no power to the IAC. The problem is in the wire from the junction you found to the IAC valve.
That was why I suggested the jumper to get the IAC power again, they both receive the same bias voltage from that junction.
Unless it is faulty it won't be open continuously.
Here is a video showing the valve.
Sunday, December 25th, 2016 AT 6:07 AM