A stepper motor like the IAC need to have power and ground applied to different terminals to make the armature turn a complete revolution. Look at the gm wiring diagram for your system and you'll...

Here's a homegrown way to set minimum air that I learned with carbs and still works today. Get a strip of paper about 1/4" to 3/8" wide and maybe 5" or more long. Open the throttle and insert the...