idle control unit voltage testing
 

im tryin to see if the idle control module is gettin power or not. I tested from pins 2 and 4 on the harness, it had 13.7v at "idle". at the idle valve, with the harness hooked up, it gets 0v, with it unhooked, the harness end has 13.7v. and fwiw, the valve unhooked had around 15ohms. does this mean the valve is shot? i swapped valves from a junkyard car, and it the idle was still bad.

What model of Hummer is this?

Blonde ?
;)

"you can tell it's close to Christmas"
 

"Youse guys" show no mercy.

82 380sl.....still stumped

The best way to view the control of the idle valve is with duty cycle or current in milliamps. Typical current will range from 6-900ma. Duty cycle is actually the best view if the car is idling too high. The system will crank out a maximum of around 70% ON duty cycle trying to close the valve. If the speed is high and the duty cycle is at 70% either the valve can't close far enough or air is entering the motor somewhere wrong.

If you loose all voltage when the valve is connected I would look at the OVP for source voltage. Loosing the voltage like that is an indicator of a weak circuit. one that won't hold the load. The load should be able to hit 900ma trying to close the valve.

rough idle on 89 300TE
 

I'm fighting a similar problem (rough idle, worse under AC load, especially when warm) with my 89 300TE. I've check the ICV, current looks good, but doesn't change under load. I also have a problem with the Cruise Control cutting out after a minute or two. Is it possible these two problems are related? My searches indicate that some cars had an integrated EA/ISC/CC unit. Does mine? how can I tell? I've checked fuel pressure, coolant temp sensor, throttle actuator. What next?