Wiper Motor Wires
This probably won't help, but I was just looking at wiring on my 67 Barracuda too, trying to determine what I need to do to put reverse light wiring back in my car. The reverse light wiring is supposed to go through the same section of bulkhead connector (closest to the fender of the three sections) that the wiper motor wiring goes through.
I noticed that the only wires connected to that section of bulkhead connector on mine were three wires from the wiper motor, and they were not using the original connector. They were individual wires with a little heat shrink on each wire. Mine is a standard 2 speed wiper and has the standard 2spd switch, not what yours sounds like being the variable.
Attaching a picture of my 2spd wiper motor...
This probably won't help, but I was just looking at wiring on my 67 Barracuda too, trying to determine what I need to do to put reverse light wiring back in my car. The reverse light wiring is supposed to go through the same section of bulkhead connector (closest to the fender of the three sections) that the wiper motor wiring goes through.
I noticed that the only wires connected to that section of bulkhead connector on mine were three wires from the wiper motor, and they were not using the original connector. They were individual wires with a little heat shrink on each wire. Mine is a standard 2 speed wiper and has the standard 2spd switch, not what yours sounds like being the variable.
Attaching a picture of my 2spd wiper motor...