Is there more than one main electrical feed wire on a ‘89 GT? On older Fords there was just one hooked to the positive side of the starter relay. My ‘89 some of the wire loom is missing.
You have stuff that is electrified all the time like headlights, pw, pdl and brake lights. Then there is stuff that is electrified by the key switch, ignition, radio, havc and wipers. I'm sure this is a short list, what you need is a assembly manual, the haynes or chilton you buy in the ripoffzone,
Did you get that EVTM (I think that is the electrical diagram) that someone was passing around? I think it was for a 89 model.
PM me your email address and I will send you a complete Ford Factory 89 Mustang electrical diagram set. The zip file is 2.5 MB and is too big to fit through Stangnet's email gateway.
The plug shapes on the diagrams match the plug shapes on the actual plug. The diagram is divided up by the layout of the car. The first diagram is for the very front of the car, and it works its way to the rear of the car page by page.
They are in a zip file format to reduce the size of the package. If you don't have Windows 7 or Windows 8, or later, you’ll need WinZip or other Windows archive tool to extract them from the zip file.. See www.majorgeeks.com - Download Freeware and Shareware Computer Utilities for a free download.