Under the black tape is as follows
Black/white wire splits into black/white and brown wires to the balast.
Black/blue wire splits into the white and yellow wires to the ballast and a white/black wire to the coil+
The blue wire is straight through to the coil-
I've got a '77 620 4x4 that's giving me no spark. The truck was not running when i got it.
This is what I'm working with.
The two red wires where connected when I got the truck.
I've looked through tons of diagrams, but haven't found a setup like this with the dual resistor. Fuses are all good. Ignition switch works.