Welcome back to the Yellow FoxBody Guy site. In this post we discuss woes of the FoxBody Mustang wiring and offer a few tips on electrical system inspections. (check out the video on the YouTube channel below for DIY Power Windows) For all you guys that like “Drawings” a link is provided below to download wiring diagrams for 1979 to 1986 FoxBody Mustangs.

As I stated in the Yellow FoxBody Guy YouTube video wring is my nemesis and most of you can probably relate. It’s not that I don’t understand how electricity and circuits work, its just that its down right aggravating. Trace this wire out, trace this wire out, oh the fuse is blow … WHERE THE HECK DOES THAT WIRE GO? My point is you have no idea how frustrating an electrical problem can be until you have had one.

Every car has a history! Unless you have owned the FoxBody since day one, you have know idea what the it’s been through, who’s worked on it and how it was repaired and whats the electrical history. Below is my check list to help sort out those FoxBody Gremlins.

Finding Those Electrical FoxBody Gremlins:

1. Battery: Check the case for cracks, bulges and leaks, and check the terminals for tightness and the presence of corrosion. Also make sure the cables are secure and free of corrosion and that the hold-down is secure and is not touching any cables. Test the battery for minimum voltage-usually 9.6 volts-under a current draw at three times the ampere-hour rating of the battery. If the battery is not a sealed type, check the fluid level and the specific gravity of the electrolyte.
   
2. Starting System: Inspect the starter wires, terminals and ground points for looseness and signs of corrosion. Measure the voltage drop during starting; a large drop could indicated excessive resistance. Inspect the neutral safety switch or clutch switch if applicable.
   
3. Charging System: Inspect the alternator for burned or charred areas, which would indicate shorting or grounding. Always make sure the proper gauge cable and wiring is being used. The connections should be clean and tight. Test the alternator for proper output voltage.
   
4. Distribution System: Check the wiring harness for repairs and damage. Wiring repairs with improper wire gauge or materials can cause excessive resistance and current loss problems. Inspect the fuse panel to ensure that proper fuses are being used.
   

FoxBody Mustang Electrical Diagrams