Join Date: May 2014
Location: Nature Coast, Florida
I actually sold car audio equipment back in those days.
Wiring was very often unique to the mfg, sometimes even the model.
If you still have the manual, a proper wiring diagram should be contained within.
If not, google the model #and see if there is a manual available for download. Once you know what wire is what on the head unit, the battle is more than half over.
Hope this helps-M5
1989 Graduate S3