Another Mopar Off My Bucket List - Barracuda Fastback
I was fully prepared to strip off the electrical tape that bundles the harness, but the wiring all looked so pristine that I had a last second change of heart. During inspection I could see that the majority of the wiring that I'd be unwrapping had nothing to do with the light circuit. Instead I focused on the schematics.
As I isolated power from each wire I was able to determine that the pink (power supply) wire that fed the light switch was not the issue. The damaged section of the pink wire seems to have been caused by the 2 black wires that it lay against. One of those 2 black wires feeds the tail lights and the problem still exists when it's disconnected downstream. The other black wire runs to the dash light dimmer switch. Originally I had ignored that second black wire because I still had the problem with the dimmer switch disconnected.
The schematic showed the second black wire junctions with a yellow wire with a black tracer. That yellow/black wire is part of a headlight warning buzzer circuit. The 2 wires (black and yellow/black) are tied together on the female plug that attaches to the dash light dimmer switch. When I separated the yellow/black wire from the black wire my problem went away.
With the instrument cluster, ash tray, and glove box removed it's much easier to see most of the wiring. - The dash frame still obstructs some of your view and the shifter handle prevents easy access to the wiring that has to be accessed from below. Last night I searched for the headlight warning buzzer but couldn't find it. As far as I know this car does not have one.
Today I'll resume tracing the yellow/black wire. Maybe there is a warning buzzer and I missed it. - Or maybe the opposing end of that wire is contacting ground.