Re-Wiring 1975 Plymouth Duster
it does have a rear defrost grid, yes it does have the fender tag.
OK. Since it has the defrost, no need to decode the tag.
It means we'll have to adjust the working diagrams using those options.
Please look at the diagram in post 18 to get the basic concept. (There is no such thing as a 'high speed' wire )
Power comes from either the battery or the alternator. In a standard '75 they are spliced together in two locations, one inside the car and one inside the engine bay.
A car that came with redefrost was wired a little differently and we'll get to that.
no power running to the rear lights, front lights, or dash.
Your choice on how to approach this. I don't know that one is beter than the other. Just that one may be more appropsiate to your situation.
1. Solve the lights issue first.
2. Get an overall understanding of the main wires, what they do, and what has been modified. Then first the lights and whatever else you decide.
The service manual is enroute,
There's a link I posted earlier to a downloadable pdf for '75. Some bits are cut off but its mostly there.