67 Barracuda Dash harness install
Here is some of the insanity that was going on under the hood so it's hard to say what caused what?
Not as hard to figure out as it looks at first glance. You just have to look at it as a puzzle. The wiring diagrams are the crib sheets. The terminal cavities and wire colors are the reference points. Each had a function, which is shown in the wiring diagrams.
The box on the inner fender with the big plug is not from '67. Its a Chrysler made electronic control unit (ECU) that someone installed. The wire colors on the ECU harness can be found in the old Direct Connection/Mopar Performance bulletins, copies of the instruction sheets and some other places. Folks here can help you get copies of those. Adding a Chrysler ECU plug to a '67 should not have have caused any electrical problems. I had one on my '67s original harness.
Wires through a hole in the firewall are part of some jerry rigging. Without a grommet, that will be a problem sooner or later.
Those crimp connectors are an OK method of joining wires if the crimp is good.
As far as what happened, its not neccessary to reconstruct the failure scenarios completely. But it is helpful to figure out what circuits were overloaded.
Whatever happened went down in one of two ways. Either a problem occured and someone made modifications, or someone made modifications and problems occured, which were then fixed with a little jerry rigging.
The bulkhead connector shows damage on P and a lesser amount on Z.
P carries the power from the alternator.
One thing to keep in mind is electricity flows from the highest voltage source. That's normally the alternator. You'll notice when the engine is running the system voltage is around 14 Volts. When its not running, or the alternator can't produce enough power for whatever reason, then the battery becomes the highest voltage source and system voltage drops to around 12.5 Volts.
When the ammeter is correctly hooked up, it shows whether the battery is discharging or charging. When you take the instrument panel out, if there was overheating on any of the wires to the headlight switch, ignition switch or ammeter, you'll see the evidence. At this point there is no reason to rush anything off for overhaul. Considering your location, overheating at the bulkhead and other connections simply due to oxidation, corrosion from water, salt, and things getting shaken around on the roads for 40 years is a reasonable possibility. Take the harness(es) off, see what you find and start pricing out reproduction wire harnesses.
