Got a bug in my brake/ taillight section. While in the process of putting in a new brake light switch, the left brake lights quit working. When I turn on the headlights, the left tail lights will come on, but the right side does not and the brake lights quit working on that side as well.

Cant find any obvious culprit, anyone have this happen before?

First, do you have the old switch and why were you replacing it? Then, when the issue is happening, wiggle test the trunk harness. Did you install new bulbs as well? The brake/tail lamp sockets are finicky to say the least as far as the ground connections go.

Jeff,

I do have the old switch, I replaced it thinking it might be a part of the issue I am seeing as I have never had anything like this before. I replaced it because it was acting up -sometimes working and sometimes not- I was at the end of the adjustment for it. This started (no lights on the right side) with the old switch as I mentioned so I am heading towards something else, thinking it might be under dash as I never touched the brake lights in the trunk- never even had it open while replacing the switch. No new bulbs. Maybe I bumped something or? I did accidently tug on the lines under the dash going to the switch I replaced

Could be a bad ground or an issue with the harness connector. Pull up the drivers sill plate, peal the carpet back and then lift up the galvanized plates covering the harness to the rear and start inspecting.

Are the turn signals working as expected? Test each direction and the hazard flasher with lights off and on, both with and without brakes applied.

I will give it a try tonight and see what I find. Thanks Jeff.

I will check it out tonight Jim.

ok, so I lifted the galvanized plate and did a quick inspection of the wiring- did not see any nicks or bare wires.

I got under the dash and started looking for loose wires, bare wires- etc. did not see anything obvious.

On my first attempt tonight- I had turn signals working fine with the lights on and brake pedal depressed. (no brake lights though) Also worked without the lights on and the brakes on but the side that was not blinking would dim slightly when the ones selected to blink were blinking. (car not running) Turn signals work fine with car running.

Both brake lights were working now (vs only the passenger side before) with the lights off. When the lights are turned on the brake lights stop working.

left for a few minutes and came back.

slow, slow turn signals with parking lights on, even slower (almost not any) with lights on (car running or not)

No taillights when lights are turned on (had the left side initially)

Have both brake lights with lights off.

WTH

Starting to sound like a turn signal switch to me.

Check the switch connector at the bottom of the steering column.

Possible.

The only time I had a really bizarre rear lights/brakes/turn signal mishmash issue, it was the turn signal switch. I think the dual filament rear bulbs handling three lighting functions, passing through multiple switches makes diagnosing the fault from the schematics much more difficult.

Update- I had everything working good last night when I quit. The nearest I can tell it was a ground issue in the back harness on the passenger side. I am going to put things back together and test it this weekend when taking it out for a drive- we will see! Thanks guys for the help on this.

After several drives this weekend, it looks like it is solved!

Cool, glad you got her fixed!