Although this car has suffered several odd electrical issues, most have been too intermittent to support a proper diagnosis.

This current issue is the first consistent problem.

What is happening?

With lighting switched off (headlights, corners, etc) nothing unusual happens. Normal function, no issues with the panel.

If I use the left signal, With the lighting switched on, the bulbs at the driver's side rear light incorrectly, and appear to short themselves out. The signal lights flash and two top rear-end lights flash faintly with the signal. The bulb out warning on the dash also glows faintly or flashes.

Applying the brakes with the lights on always cause the bulb-out warning to faintly glow.

If the signal is still on after I release the brakes, the bulb-out indicator flashes in time with the signal (actual signal on the outside function normally)

Lights On, Left Signal On, Brakes On - the signal itself slows down noticeably. If I put the car in reverse, the whole panel is drained and I get nothing.

I've got a video of this that I can post if the description is unclear.

Also, the ground wire connection is blackened and the plastic around the panel's ground terminal is slightly melted.

Clearly some sort of short - likely current hitting the ground maybe some problem with the brake light circuit...? Unsure, I just can't find the problem


What Have I Done?

Examined and traced the wires from the panel to the rear end grounds. I checked the harness grounds under the rear seat. There's nothing weird here that I can find. The tail lights ground to a bolt just below the trunk hatch. I checked continuity and found no bad connections or evidence of shorting.

There's a bulb relay at the rear panel. Pulling the relay stops all the weird behavior with the signal, but the other lights things stop working. I replaced the relay with two different units and it makes no change at all in the malfunction.

I opened up the plastic channels for the wiring harness on both sides of the back. No pinched or damaged wires, no evidence of anything out of the ordinary. No scorching on anything. I was unable to affect the signal problem by doing anything to either set of wires.

I also removed the last vestiges of an old "car phone" system. I had hoped it was related to the electrical, but nothing was hooked up and the problems continued after I had removed all the wires, mounts, screws, etc.


Ideas? Differential Diagnosis?

I have not started tearing into the dash yet, but I'm pretty confident that the problem is up-front somewhere.

Any ideas where or what could be causing this localized problem?


The passenger's side electrics work just fine.


There are plenty of other electrical issues. Since this problem became consistent, I've experienced intermittent horn function (despite checking and replacing the wheel contacts). Right now it's not working. The driver's headlight low-beam cut-out suddenly, but came back. I can't seem to stop the car from blasting heat even with everything switched to cool. One of the HVAC servos under the dash had to be unplugged because it was constantly clicking. The sunroof opened itself while I was sitting in a drive-through (foot-on-brake).

Fuel pump has been working, but hard to say when that problem might return. It's ground had the same scorching as the tail panel ground - despite being on another wiring harness.

There's got to be something hot cross with something somewhere. If it were something shorting right to the body of the car, shouldn't much more being going wrong? Do any of these symptoms point to any one thing or one place in the car?