Hello all I have a 94 Ranger with the 2.3 engine. Having an idiling problem when the engine is idiling, how much voltage should be going to the idle air valve. Thanks in advance for any info you can tell me. Norman

 

IAC Valve gets 12volt on the red wire with key on

The computer controls the Ground on the other wire, it pulses the ground to vary the voltage, this is called pulse width modulation

If you use a sewing needle to pierce this ground wire and use a meter from battery positive to this pin you can see the voltage/ground being applied by the computer
There is no "set" voltage, computer adjusts the voltage to raise or low RPMs for this specific engine
The RPMs are the target that decides the voltage

You should see about 7volts at warm idle, more volts = higher RPMs, so cold start might see 9volts, higher RPMs
As said there is no 8.5v = 1,000rpms, doesn't work that way, computer is constantly changing voltage to maintain 1,000rpms, and its very accurate +/- 4rpm usually