i have just put a ZC in my 89 CRX Si. my ZC didn't come with a wiring harness so i used the one that was on the Si motor. there is a two-wire plug on the wiring harness that is close to the alternator plug that i can't find a place to plug it into. is this plug not used? or am i just blind? tahnks for the help.

 

i dont remember... umm. i htink i had one green plug that i didnt have to use .. but i cant remember. sorry .

 

This should hopefully answer your question.

http://fourthgenhatch.com/zc.html

 

Look on the back drivers side of your Si Intake Manifold and then look at the back of the ZC Intake. Your Si had a Fast Idle Control Solenoid (item 11 below) and the ZC doesn't. You won't use the extra plug you are talking about.

 

http://www.dmoore.com/crx
all u need