IAC Voltage

[Dandxj]

1990 4.0L - I know that the ECU controls the IAC Motor, but does anyone know the voltage of the signal? Is it 12V or some reduced voltage?

I am trying to figure out why the motor pintle is staying in the retracted position(high idle). Yes it is clean, new BWD IAC and TB is clean. I had the same issue with old IAC, hence the new one. I have to put a piece of duct tape over the passage on top of TB to keep the  idle down.

Thanks

[cruiser54]

How is the GROUND at that connector?

 

I'm gonna guess it's 12 volt. 

[Ωhm]

Check B+ Latch Relay circuit. Relay supplies 12vdc for IAC Motor via the ECU.

[Dandxj]

Thanks - I am seeing only 10 volts at the IAC. So somewhere I am losing 2 volts. I will start by pulling the ECU and cleaning the connectors.