Had the whole interior out and front end off this winter. Disconnected all the grounds i could find before welding. All left to do is clean and install the seats. Loose fitted the fenders, liners, and core support. All wires back in place except the sealbeams and park lamps cause thier still out. Everything else works. Have power at fuse. Do the front lamps have to be grounded for the rears to work? Did i miss a ground for the tl-lps? Only other thing i can think of damaged the harness from block to rear while everything was out..
No your front lamps do not have to be grounded to make the back work.
I know this because I completely installed and tested the rear wiring before I installed the front wiring harness. The only thing I couldn't test was the flashers.
Possible issue is that the wire for tail lamps came loose from the light switch. You could start from there. Probably easier though to check for loose connections, damage, or ground issues starting from the tail light sockets and work you way back to the switch.
If you don't already have one, a wiring diagram will help a lot to understand the whole circuit as you work through it.
Thanks, thats what i thought. Gone all weekend, so hope'n to find problem tonight. If remember'n correcty, the brown wire is hot, and theres no power in trunk. Will check at the switch next.
Found it. For some reason previous owner had cut the brown between the switch and harness connector. They where just twisted together and taped. Must of pulled apart while rewire'n some of the others. Good thing it happened now cause it couldnt be seen from below. BTY, it also powered the front lamps.