I have the older style of high idle kit and the other day that I was diving and got a p0113 code. Pulled the code and found out that it was the IAT temp voltage was to high. I tired with two different code readers and couldn't clear the code. I pulled my high idle kit off and plugged the factory harness back into the sensor and was able to clear the code and have gotten the code back. Is there anyway that I would be able check to see if I have a short of some sort in my wiring or check the switches? Also from time to time I would select the 6 cylinder and then it would switch over to the 3 cylinder high idle with out me selecting it. Would like to have my high idle back up and running. 

Edited December 16, 20159 yr by Me78569

The issue is VERY likely in the ground wire running from the IAT.  It is the Bare wire in the harness.  I am betting it is broken.  

 

Use  a multi meter on the "A" pin of the IAT plug, either of them, and test for continuity to the back of the switch where the 4 resistors come together.

Edited December 16, 20159 yr by Me78569

Do you know where the ground is located?

From looking at my old switch its on the IAT side of the plug. The 2 black wires come together to a bare copper wire this is the ground. Now it goes all the way forward to the switch where it ties to all the resistor before the switch.

Pin A of the switch is the ground for the IAT,  You should see A on the plug itself.