2006 Saturn, dome light turns itself on when it's parked.

The charging system on your vehicle is computer controlled . The ECM - engine computer turn's on the battery light if it think's there is a problem . Sends a message to the instrument cluster over the class 2 serial data network . Have you had the vehicle checked for DTC's diagnostic trouble code's ?

Sounds like you either have a light staying on in the glove box or under the hood. If that's not it, then you may have a relay that does not turn off. This sucks because there is so many of them and finding it can be tricky

Double check all connections...Check all under hood for any loose wires........Do you have it in park..?....I really need engine size and mileage.....

Your battery is not charged and gets drained constantly, dome lights doesn't take much voltage to be lit. Get a voltmeter and check on the battery. Engine off it should be all charged up and 12V ish. Try to start your engine, should be 13-14v charging, if not, then it is your alternator not charging or SOMEHOW your battery doesn't receive enough charging from the alternator.
When you turn on the headlight while engine is running and died off because the alternator some how couldn't supply enough current to power both headlights and motor ignition system
Get your alternator tested, before that all connections between alternator and battery is NOT LOOSE, or broken or damaged. Then go to auto electrician. Then sort out your fuses later.

ck. & see if it's in park or try neutral

I had a 2006 Chevy Optra that wouldn't shut off as well. When I opened the door it would turn off but as soon as the door was closed the dash lights would come on dim and kill the battery if left long enough. If i pulled the I/P fuse in the engine compartment fuse box it would solve the problem but it killed the dome light as well. Pulling the cluster fuse or the wiper fuse from the i/p fuse box had the same effect....it was a real stumper as alldata had no listing for a 2006 Chevrolet Optra so I couldn't find any wiring schematics at all. I did a bit more research and found that the Suzuki Forenza is the same car. i got a wiring schematic and found out that the dome light module/key-in buzzer is actually in the dome light itself. I unplugged the dome light/module and jumped the orange(batt +) to the pink(ign) that comes directly from the I/P fuse and the car would stay running after i turned the ignition off. I cut the pink wire and installed a diode so that battery voltage couldn't backfeed to the I/P fuse. It's been three days now and every time i turn the ignition off the car shuts off, just like it's supposed to. A faulty dome light module seems to be the problem and a $3 diode fixes it. The people that own the car have spent hundreds of dollars trying to figure this problem out and didn't want to spend another $250 for a module. I hope this helps somebody as it seems to be a popular problem.

When this happened to mine it ended up being a bad door switch. The alarm, dome/map lights and electric door locks are all connected to the door switches. It cost $65 for diagnosis, parts and labor at Saturn of South Burlington VT

you need to replace the turn signal switch,its loose and making contact when it should not,,causing the headlamps to come on,replace the switch,,like $50 for the new part,not too hard to install

it sounds like you are having a problem with the ecm which is the electronic control module which is the BRAIN of your entire car. Also when this happens everything goes haywire as if the car is acting retarded because the ecm is not receiving the proper codes on how to perform and remember the ecm is a computer that could have corrosion or rust on the connection points. check this ok that might help.

On the 01 Lincoln it has something to do with the keyless pad on the door press and hold button 9-0 till the green light around it goes out!