Hey y'all! 99 xj. I noticed when I tap the brakes some times my interior lights, and parking lights come on. 3rd brake light stays on. I also noticed yesterday my rear wiper comes on (when the switch is hit) but won't shut off unless I turn my lights off? Works perfectly fine when lights aren't on. Any thoughts?

 

sounds like a classic bad ground. will need to locate a FSM and wiring digram and see where the grounds go. start by cleaning the body ground near the battery

 

Here's the cargo bay ground points (left side, behind spare tire rack).

You might try disconnecting G304 and see if the problem persists. If the problem goes away the circuit for the listed systems has a fault (maybe).

Many times the wiring that goes to the liftgate from the body, through the rubber looms, gets chafed and shorted out.

 

this could be a issue. Why do I say this? I took it apart the other day to install the upper quarter guards.