I have a 2002 Escalade AWD and for a week now my interior lights have been on constantly. I've checked the dimmer switch. I've opened and slammed shut all doors including hatch. I've checked the fuse as well. I've also noticed that when i'm driving sometimes they will flicker off and back on and stay off for a few minutes, but ultimately come back on. I believe the only thing that is saving my battery is the automatic shutoff on the truck. It will force them off after 10 or 20 minutes or so. I've had an aftermarket alarm on the car for about six months with no issues. The funny thing is my alarm works where the led comes on when you open a door and the led turns off when you close the door, or the led comes on when you trigger the shock sensor, so this kind of confirms that I am not seeing a door open, because the led will be off while the interior lights are on. Could it be the door switch anyway? Where are they located in the door? Is there anything else I should check?