If you have your indicator on iether left or right it will leave the left or right front and rear lights on this is for parking on the street so no one drives in to your parked car and you will get the beeeeeping sound. if this not being done i dont know what it is.
 
Used to have a Vectra GSI and it also did this, not sure on the drain on the battery as i have never used it, but i think it might as my son switched the rear interior light on yesterday and i woke up this morning to a flat battery, not sure if this is normal or if my battery is on the way out, this time of year is testing on batterys.
 
It's for if you're parking somewhere in the dark that might pose a bit of danger so want to make sure your car is visable.

Like Stuart says, Parking Lights.

I've never used them though so not sure on the battery drain.
 
It's for if you're parking somewhere in the dark that might pose a bit of danger so want to make sure your car is visable.

Like Stuart says, Parking Lights.

I've never used them though so not sure on the battery drain.

I use my parking lights alot, only for short periods. no problems on battery at all.
 
I only found this out when changing my sidelights for LEDs. The switch was off and the bonnet up yet the light was still on, opened the door, beep beep beep. Thought WTF?!? until I checked the indicator stalk :lol: :redface: