Reverse lights on with Headlights

Hi. I am new here and acquired a 98 XJ 180,000 miles about this time last year. It was in good condition but like any used vehicle has been plagued with little gremlins from work done by previous owners. I have been able to correct most of them but I don't know where to start trouble shooting this one. Electrical systems are not my strong suit and any help would be greatly appreciated.

Problem that I have is when my headlights are turned on the Reverse lights come on. Also vice versa when the vehicle is in reverse the Dash lights come on. Not sure if the headlights come on as well in reverse, I will have to check.

Is the Cherokee wired for trailer lights ? It seems logical to assume that there is a physical wiring issue and probing the tail light and reverse light circuits with a volts/ohms multi-meter will help locate the fault. Start at the taillight and tailgate wire harness plugs behind the spare tire area plastic trim. Check for wire continuity, stray voltage, and good ground connections.

All the exterior lighting is switched power with constant ground, so something is sending power to the reverse harness when you put the lights on. Most likely explanation is that there is exposed wiring in one of the tail light harnesses, and power from the running lights is bleeding into the reverse light circuit.

Yes it does have the trailer wiring harness appears to be factory. I had a bad feeling this was probably a physical wiring issue with a short somewhere, not a faulty switch.

Guessing this is something similar to the issue I had with with front speakers with broken and exposed wires. The speaker wires were broken but I also repaired several other wires that became exposed.

I will try and get it in the shop this weekend and start working on identifying the problem, unfortunately its near or below zero this week so it might get put off for a little warmer weather.

Thank you for the advice I will keep you posted on what I find.

If the trailer wiring is plug and play, it is simple to remove for diagnostic purposes.

check all of the grounds as well.

When the grounds for lighting sucks it will find alternate paths, usually through another bulb.