66 mustang wiring repair

theresasudd

New Member
Dec 19, 2020
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Arkansas
Hello I’m new to forum. Here’s my deal my wiring around top of engine is damaged. Apparently coil was leaking and somehow some way caught fire. Never knew that could happen but it did. The fire was not that bad we got it out in less than 5 minutes. Coil was mounted on top passenger side of engine between carburetor and alternator. I have good wire at at the harness behind engine where it connects by firewall on drivers side and then good wire at components(alternator, starter relay, etc) but good length of several wires in between burnt. I do not have the money to buy a new harness. In theory one would think easy patch but that is not the case. I bought the car 3 yrs ago from a local classic car restorer/resales lot who apparently takes short cuts when restoring. I know the wiring before fire was not as was from factory because the colors do not all match diagrams I’ve found on line. We patched the wiring but there is an issue somewhere because it does not seem to be charging. I know that many of you are going to recommend just buy new harness and I honestly wish I could but I cannot afford it. I’m normally pretty good about googling my problem and resolving it. I’ve looked at voltage regulator wiring harness has one wire that is gone but it was not due to fire it is clean break/cut at connector looks like it has been that way for awhile so I do not that wire is
 
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My advice would be find a wiring diagram and chase wires from each component at least to the firewall. "patching" a harness can get you by, but these harnesses are now about 55 years old. Be careful, you already had 1 small fire, don't contribute to a worse one.

V8 or 6? Do you have an original alternator? Do you know it's good? Could be the short killed it. Original regulator or solid state? Lot of unknowns.
 
My advice would be find a wiring diagram and chase wires from each component at least to the firewall. "patching" a harness can get you by, but these harnesses are now about 55 years old. Be careful, you already had 1 small fire, don't contribute to a worse one.

V8 or 6? Do you have an original alternator? Do you know it's good? Could be the short killed it. Original regulator or solid state? Lot of unknowns.
V8, it is original alternator and regulator
 
From Alternator you have 1 wire that goes to the battery (probably to the starter solenoid) and "A" on the regulator. Also from "S" on the alternator to "S" on the regulator and "F" on the alternator to "F" on the regulator. The "I" on the regulator is for the exciter voltage and goes through the dash light on a non-gauge. Decent pics can be found with a Google search for "Ford alternator wiring".

I might take this opportunity to go to a 3G alternator and get rid of all the hassles. If you have a pick-a-part you can get one off a Taurus that will have long enough wiring to do whatever you need to do. It will be way cheaper than an engine harness, will get you a better alternator and much newer wiring. You will lose the amp gauge which is OK with me anyway.
 

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