This problem has been plaguing me for about six months now, and I can't seem to figure it out. I have been extremely busy for the last six months or so, but finally have a little free time to devote to fixing this. It started with my trip od mileage being canceled every time I shut the vehicle off. Then i would end up with a dead battery occasionally. I have the auto-on headlight feature, and one evening came back out into the garage and noticed the headlights had come on. This has happened now, a number of times. I'd get in the habit of making sure the headlights were turned off each time I'd shut down the vehicle, get complacent, and eventually go back to my old habits. all would be good for a while, then, dead battery again. I will admit that I am a very poor electrician, but have been researching this for a while and haven't found anything that addresses this issue, I am fairly certain that the odometer resetting and this headlight issue are related. Also, I have been having an issue with the drivers side dome switch going funky now and then. Is it possibly as simple as perhaps a headlight relay? I don't want to start throwing parts at this, as we all know how spendy that can get.To preface, all grounds have been checked, at least the ones I am aware of. Any ideas as to where to start to look?

Bump

Seeing as how your having issues with the drivers side door switch, I'd start there. That switch is what controls the auto lights to turn off when you open the door. There isn't much to them so removing the switch and cleaning it with electric cleaner or even brake clean might make it work better. You could also try swapping the switch with one from the rear doors and see if that helps.

Thank you sir. I will start there.

Just an update, removed and cleaned up the door switch, and re-installed. Seemed to have fixed the trip odometers canceling out every time the vehicle was turned off. Also, have not had the headlights mysteriously come on while the 4Runner sits overnight or in the parking lot at work. Time will tell if this fix cured both problems, as I have gotten in the habit of ensuring that the headlights were turned off at the stalk, and honestly am a little gun shy to leave them on auto after so many dead battery occurrences. Will report back if there are any changes