Unfortunately this won't be extremely helpfull, but sounds like a short. Is there a lot of moisture in the air on the days when this happens.
I had a similar problem in another vehicle. On damp days, like really humid, or it just rained or something, the ignition wouldn't work. Turned out water was getting in the wiring.
Best idea I have is start with the brake pedal, there should be a sensor connected to it, and start looking for corrosion in or around connections, and keep following the wires. Not sure where the wires could cross with the other lights as I am new to jeeps, but it's a start.
The lights are ran I series, meaning if you put power to the back parking light wires the front will turn on as well as your dash lights. My best suggesting would be to look at the back lamps and move up also replace your rear lights first.
I'd check the tail lights for a proper ground. If they aren't grounded well, the brake lights will "search" for a ground, which will back feed through the marker/ tail light circuit. Have you recently put tail light guards on it?
i'd check the tail lights for a proper ground. If they aren't grounded well, the brake lights will "search" for a ground, which will back feed through the marker/ tail light circuit. Have you recently put tail light guards on it?
Just out of curiosity, does anyone have a link to TJ wiring schematics? I'm sure most of us will find them usefull in the future anyways, and maybe I could provide more usefull information to partstj. I have some limited electrical experience but I am lost without a schematic or access to the vehicle.
Just to clarify, I meant more usefull as in info I have given so far, not you guys. I am learning some good stuff here.
I had a chance to work on it today. I removed the taillights from the body and wire wheeled the screws. One back up bulb had fallen out of its socket, and it was an 1157 instead of an 1156. Checked the other side and it was wrong too. Went to napa, bought some new bulbs and a 194 for the side marker that was out. Replaced the bulbs, checked all the lights, everything checked out ok. Turned the lights off, stepped on the brake, the dash lights came on. I guess I will change the brake light switch next.