Found this on the 'net so I'm just posting as I have no idea about the validity of the response.
Why do the interior lights stay on when car is locked and all doors are closed on a 1997 Jeep Grand Cherokee?
DO NOT REPLACE THE BCM!!! TRY THIS FIRST!
I found the way to fix this. It's a bad switch in either/both the driver or passenger side front door. The switch is located at the bottom of the door opposite the hinge. The switch is used to tell the car that the door was unlocked and to turn on the lights. If you pull back the door cover on the bottom (You do not need to remove the cover completely) and pull back that plastic you will see the plug for the switch down in that bottom corner. Just unplug one switch and try closing and locking the doors. If the lights still don't go off try unplugging the other switch and doing the same.
I'm not sure how much these switches are, but If you decide not to replace it you will see the following effects (There may be more, but these are the only ones I'm aware of): 1.) The lights will not turn on when that door is unlocked. 2.) If the alarm is set and you unlock only that door and enter the vehicle, the alarm will sound.
there are 2 switches 1 at the front and one at the back of the door frame... the back one tells you that the door is a ajar for one.... maybe other things also
the front one turns the lights on...
check you drivers' door hinges to see if they are worn... pick up on the door to see if it moves up...
if they are worn enough it will let the lights come on.... I have put several layers of duct tape over the switch to make up the difference
maybe you could hold both switches by hand to see if that solves the problem
I do have tape on both of my driver door switches... I had the broken weld hinge problem.... not quite fixed right ... that's why the duct tape to keep the lights off.
94 Grand Cherokee ... 332,000 miles
5.2 liter 242 :)
Rancho 5000 steering stabilizer
I checked the dimmer switch is not in the on position.
the funny thing is when you start the jeep, the interior lights go off. And opening the doors will turn the interior lights on, shutting the doors will turn the lights off. This makes me think the door switches are all working.
When the ignition is turned off, the interior lights instantly pop on and never go out.
Is there an interior light relay with a timer delay and somehow it is stuck on?
Do the interior lights have a time delay feature so they stay on for a few seconds when the door is shut??
Im willing to bet you have a bad wire somewhere between the battery and the BCM. Probably in the junction block under the driver side dash. Your symptoms are similar to what I was experiencing when I bought my 2000 WJ a few months ago. Basically, the BCM (which controls all of the lights and well...pretty much everything) wasn't getting any power with the ignition off. So, my headlights didnt work, horn didnt work, interior lights didnt work, other courtesy things didnt work until I turned the key to the on position. Then everything worked as they were supposed to.
I took mine to the stealership because the problem eventually affected the SKIS and I was no longer able to start the Jeep either and had to have it reprogrammed for my key. They charged me $180 to find and replace the bad wire.
You may not be experiencing all the symptoms I had because #1 I'm not sure if the BCM does the same functions on a ZJ and #2 it may not be the same wire and #3 It may be the same wire but may not be completely bad. So it is getting a little power or intermittent power.
The stealership should be able to hook it up to a DRBIII and tell if the BCM is getting power with the ignition is off. My local stealership didn't charge me for that, but they may charge you for 30 minutes labor. Then when I finally had them fix it, they charged me $180.
2002 Overland - 4.7 HO, "Select-Drive", 4" RC long arms, TAG front winch bumper, 32" BFG KM's, 3" exhaust, Magnaflow hi-flow cat, Flowmaster 50 series