Wiring nightmare

[benson64L]

Im having a serious issue with the rear running lights on my 79 620. Ive re wired the lights and checked the fuses and all i can get is the break lights and driver side blinker to work. I am also wondering if the dash lights are are tied in to that circuit because they also do not work. Can anybody help me out?

[datsunaholic]

Yes, the dash lights are in the same circuit. The front, rear, side marker lights and the dash lights all are fed by the same source through the headlight switch.

[CorAce]

electrical is real hard to diagnose over a forum. do you have volt meter or some kind of indicator light and a wire diagram for your truck?

[benson64L]

I have the FSM and a volt meter. There is power at the fuse box but no power to the wires in the back that hook to the tail light ballast. I also dont have front side markers or front turn signals hooked up

[CorAce]

OK good. not to state the obvious but a circuit is a complete loop, my best advice is to take the last location you have voltage and follow that wire, checking each side of all the connections until you fined were the break is. remember the body counts as part of the loop, your grounds need to be good. its likely you have a problem in your fuse box if all these issues are on the same circuit.

[benson64L]

Cool man, thanks. Hey by chance do ya know about installing a 720 fuse box? Is it pretty straight forward?

[CorAce]

Not a clue sorry, I have really only worked with the 510's. I guessing its not that complicated.