This is for on 85 Iroc. It comes from the key switch and connects to passenger side harness.

On the 86 Iroc, no such wire exists. Maybe someone pulled it, i don't know.

What is this wire for?

 

That's for cruise control.

 

Thanks much. I've already pulled the other components of the cruise control to put in a box in case of later use. I'm soon to start a thread in "engine swap" section showing pix of the project with details of how it went and the difficulties. Plus I can put all my questions in one place.
thanks again.