Rear fog lamp problem

[Kodric]

Hello!

Around the time I pulled out a stomp with my rear bumper and the time I bent a STOP sign, the rear fog light developed an electrical issue. Since then, when I turn on the light, the dashboard light turns but the rear fog light won't. The bulb in the back is brand new so that's not the problem. And now in the winter time, when it's cold, sometimes when I turn on the left blinker, the dashboard light for rear fog light starts blinking. Around that time the left number plate light stopped working.
I suspect the mechanic working on my rear bumper did a horrible job in connecting the ground wires, but can't find the problem.

Can somebody "shine some light" on my problem?

Thanks!


p.s. I have an ABS "mod" so that's working OK.

[GECKO]

The rear fog, number plate and left indicator come from the same place.

Put the rear end on some axle stands, remove the spare wheel and have a comfy seat - it may take some time.

The way you describe it i can imagine something at or before the split of the cables between left light cluster and the Number/center stop light has caused a defect. This split is at the left frame rail near the bumper mount.

As the dash lights are LED (one direction current flow) and the indicators are (i think) reversed my suggestion is to open up the wiring loom around the split and look for the white/black wire contacting the rest of the wires.

Note there should be a well insulated crimp connection for ground, parking and stop lights.

My first bet would be to re-insulate all within 10 cm from the split and re-crimp the connections if needed.
If there is no obvious damage there my next action would be to trace the wires up into the cabin (under the left front seat). If no damage is found - go to a car electric doctor.

If i am correct the ground will be contacting with the positive for fog and indicator due to a pulled/ripped out cable for the license plate light. As a result turning the indicator will short the fog and indicate but won't have the fog light up.

[Theprospector]

R is for Runout on the fuel gauge

[JaQ]

Agree with gecko,

Sounds like some of the wires are exposed and touching the body/earth/ground of the lux, this then causes the other lights to also work when the indicator is flashing,

Is the symptoms not different when raining as that would confirm the damaged harness.

[Kodric]

Thank you guys for the help!

@ GECKO, thanks for the advice! I'll be spending some time under the truck in the near future doing some other work and will look in to it.

@JaQ, yes the problem occurs when it's raining, I suspect the salty snow in the winter is the reason for the grounding of the + to the body.

[Kodric]

For anyone searching the forums for answers to a similar issue.

When doing restoration (viewtopic.php?f=41&t=31746) I found out that the trailor connector split into the main rear lights cable. The issue was probably the power connector zip-tied to the rear bumper as I removed the hitch because it reduced the exit angle. The connector housing is meant to be permanently bolted to seal from water...
It accumulated salty snowy water and was playing with grounding, lighting up the dash.