I've got a 97 Grand Cherokee Limited with a 318ci that I'm rebuilding due to poor mechanic work, neglect, and poor maintenance. It's been beaten up and driven into the ground. But I can't figure out what is going on with my interior electrical. The interior lights come on and off randomly but stay on for the most part. I had to remove the relay for the over head lights so I could see at night. The lights in the doors are almost always on. I've unhooked all the door switches and it didn't work. Anyone have any suggestions and\or experience with this issue? It's driving me nuts.

 

Maybe check the electrical connections at the back hatch.

I believe the interior lights come on whenever a door, or the back hatch is opened (probably)? If all of the door switches are already disconnected and removed from the equation, then maybe the contacts or something to signal where the back hatch has been closed are no longer functioning correctly could be it?

 

There is also a Body Control Module (BCM) in this year ZJ Grand Cherokees. The BCM is in charge of the interior lights. You could unplug the BCM and use a jumper wire between the different corresponding pins and terminals of the BCM. Do this while looking for a parasitic type drain with a multimeter on the battery (or fuse box) to show itself when you end up putting the jumper on the problem circuit... It should be able to tell you where to go in which of the circuits to find and fix the problem.

 

Disconnecting the little wires one at a time from the BCM, until the interior lights go off and stay off might work to help figure this out for you too.

 

Try unhooking the key switches on the door locks and hatch.