View Full Version : Brake lights stay on, modified LED harness, been working fine for years

November 18th, 2017, 11:11
First off just would like say hey all, it's been awhile.

Jeep info
1997 4.0L
Modified tail lights- LED set up using a tow ready harness (followed Hammered's write up) been working fine for about 3 years

Anyway the other day found out my brake lights are doing a steady burn (looks like I'm driving around with my brake pedal pressed). I switched out the brake light switch for a new mopar one and the brake lights still stay on, including the third in the middle. Other things I've noticed are the turn signals still work fine, brake lights go off when xj isn't keyed on, hazards work correctly, if I don't have it keyed "on" or running but turn on lights, the brakes lights operate correctly in running light fashion and if I press brakes in they operate correctly. If I turn key over brake lights immediately turn on with out lights being turned on and produce the steady burn as if brake pedal is pressed.

It seems I'm past the brake switch so I've been checking my fuses and such, all are good, I did also noticed the fan for my climate controls has been engaging immediately when I key on as well. The climate controls are on the same fuse and relay as the stop signals. My question would where should I start looking for the short? I started cleaning the grounds to see if that helps. Maybe a different module or relay went bad. If anyone thinks of a different test to try let me know. :banghead::banghead::banghead:

November 18th, 2017, 12:40
Also, took off an old trailer wiring harness which helped the situation for a while but the problem returned, I'm at the point where I'm probably going to buy some new tow ready harnesses and re do the LED's and hopefully that is the cause of the problem

November 19th, 2017, 14:10
After i took off the old trailer harness, it worked for I'd say 15 minutes, what is the box under the driver side dash that the brake light switch plugs into? It's a white plastic box that seems to hold the majority of the lighting system wiring? Haven't had anyone help out with suggestions, hell at this point anything is welcome

November 20th, 2017, 07:22
Shorted with fuel pump? -- what else would run to the back thats keyed power?