The issue: The side markers, parking lamps, and tail lights are NOT working.

What does work are the head lamps, the brights, and the rear brake lights.

Installed a new front light harness last year. The previous owner of the car had the front side marker lights grounded to the front bumper brackets. I moved the ground wires to the core support, where they're supposed to be, with the other front lamp ground wires.

The front core support is a reproduction.

The light switch in the dash was bad, as it just spun and spun, so I installed an NOS switch today hoping that would solve the problem. It did not.

Checked each fuse in the box under the dash with the meter and each fuse appeared to be okay.

A few weeks back, all the lights did in fact work but just for a bit, and then didn't come back on when I turned the lights off that evening.

I tried grounding the RH side marker wire to the core support by itself but that didn't fix anything other than just make the RH head lamp very dim. When I put the ground wire for the RH head lamps to the core support it lit up without issue. I only did this on the RH side but not the LF side so not sure if I should have tried to re-establish the ground on the LH and RH side.

When installing the headlight switch, I couldn't get the little light for the switch to install so I just didn't put it back and left it buried in the dash.

What's odd in this is that the tail lights aren't working. I suppose I could try a different fuse just in case?

The front light harness is from Lectric Limited. I've never had an issue with any of their harnesses and I'm positive they sent me the correct hardness as I checked each wire.

Open to suggestions or ideas but a bit frustrated at the moment.

 

I had a similar issue in the fall after my car sat all last summer. The lights started working after I cycled the headlight switch a million times. Apparently there was oxidation on the contacts.

 

Once again, this isn't a problem that can be diagnosed remotely. Get a wiring diagram and a test light and trace the circuit until you find where the power stops.