Very weird electrical problem with tail lights. HELP
I've got my 55' f100 with 292 y block from North Carolina earlier this year. It has been converted to 12V and has the original wiring all around.
Overall very good truck , i've done just little things on it to make it better.
However , yesterday the brake lights and blinkers stopped working all of the sudden. Just the running tail lights were working.
I changed the old wiring with new connectors and wires and all started working again apart from the driver side brake light ( blinker and running light was fine). Then I changed the ground wire and hurrah, all worked.
They all worked but i never started the truck , all the tests i did were done with the truck off , just the ignition on and light switch on.
When i started the truck , NOTHING .
Only the passenger blinker worked , thats it. Any ideas what might be the issue ?
Btw I just found out that the battery is grounded to the chassis instead of the engine.
When you add the additional ground straps take a few minutes to scratch/grind/etc the paint off in the area where the strap goes. You want good metal to metal contact. It's also a good idea to use those star type lock washers as they "bite" into the metal pretty good
.

Good luck, I hope you get the lights working so that you can go drive it around and enjoy it.
Bobby









