Originally Posted by Hypersion
I did leave the switch in the on position instead of in auto. I assumed they would still turn off after a set amount of time but i guess they stay on indefinitely.
I thought it was the interior lights that were left on rather than the headlights. Sorry for the misunderstanding. I should have realized that the interior lights won't drain the battery overnight, but the headlights certainly would!
Leaving the interior lights on could happen as easily as 'bumping' the lens of the reading lights in the overhead console. If a door is open and the interior lights are on, there's no way to tell that you bumped them, but they will stay on indefinitely after the doors are closed ... well, the one you bumped will stay on indefinitely. Likewise for not closing all the doors ... all interior lights will stay on indefinitely.
Leaving the headlight switch in the 'AUTO' position eliminates the risk of the headlights remaining on. Actually, I am surprised to learn that there is no "automatic override" when they are in the 'ON' position, but there is presumably a good reason ... such as in an emergency situation when the engine is off, but lighting is required regardless of battery drain.
We have learned that the less 'fidgeting' with the GX ... the better. Everything is left in its automatic mode ... HVAC, lights, wipers, etc. so all we do is press the 'Start' button, release the emergency brake, put it in gear and drive. Likewise when we come come home ... set the emergency brake, put it in Park and press the 'Start' button again.