1999 Jeep GC - Lights go on and off for no reason

Turn what off on the computer display? We aren't touching anything...no keyless remote or anything and the lights are coming on and off. The key isn't in it...for that matter it is hanging in the house. Any other suggestions?

My girl friend's 1999 Grand Cherokee's automatic lights do the same thing. While you are driving they often act up, but then it got worse, and I would get up in the middle of the night and look out the window and the head lights would be on. By the time I went out to turn them off, they turned themselves off. We did have other lighting troubles (interior lights not working, lights on window buttons not working), but they seemed to have been caused by the automatic car starter we had put in. It appears that this type of vehicle needs 2 auto start modules.

For now we have taken the lights off the auto position. We know we can bring it into the dealer, but they want to charge $80 to plug the Jeep into a computer.

mic canic did pass the time by typing:

I have seen accumulations of crap in some. Dust buildup will tend to make them more sensitive at dusk. But even if you covered the sensor with tape it still wouldn't make the lamps go on unless the ignition was on.

That brings up a possibility. One of the sense wires brings a ground to the module when the switch is in the Auto position. If someone tapped that for a ground it could sure mess things up. One other lead senses the backup lamps (Why, I dunno). They don't give enough detail on the ultralight module to know what wire does what.

Of course this is all academic since the 99 wiring is probably far removed from my 93 schematics.

The key is "aftermarket starter". I've seen lots of hack jobs pulling power from any handy source. It needs to go back to the installer since they caused the problem. Jeep may diagnose it but the solution could be to remove the remote starter at your expense. (harness repair work is expensive and quite a few shops only talk in terms of replacement harnesses)

OK ... I had the exact same problem on my 99 GC, I would go out to the parking lot and my lights would be on. The Jeep dealership replaced the headlight switch/turn signal handle/module on steering wheel. (under warranty!!) Good as new problem fixed.