arhunter

Greetings

I have an interesting tail light issue and am looking for advise on how to trouble shoot the problem.

1999 Jeep Grand Cherokee Laredo Trim.

Issue:
When the head lights are turned on the brake lights stop working. However, when the headlights are turned off they work just fine.
The top center rear light located above the rear hatch works fine with headlights on and off.


Rear Backup Lights work with headlights on and off
Night Running Lights work with headlights on but when brakes pressed they go off and the bright brake lights fail to light.
Turn Signals work with headlights on and off
Flashers work with headlights on and off.


Attempts to repair:

1. Replaced all bulbs on both rear assemblies thought maybe some sort of overheating or short caused by one of the other buibs.
Result no change.

2. Replaced the sockets on the tail assemblies using used items from local salvage yerd.
Result no change.

3. Replaced the fuses that are part of the rear lights circuits
Result no change.

Has anyone encountered this problem?
What was your solution?

Winter is approaching soon and I need to solve this if possible with out the need of taking in to the dealership.

Thank you for reading and looking forward to your replies.

PatHenry

Likely a wiring issue (chafed off sheath or something to that effect). You might try in the Grand Cherokee forum and see if this is common for your year GC and if someone can narrow down the spot to start diagnostics. (https://www.cherokeeforum.com/f5)