Flat battery and rear brake lights..

[Kamatari]

Hi all, I'm posting this on behalf of a friend, Basically he's recently got a second hand mk5 thats giving him some problems...Throughout the night he notices that his rear brake lights are on and then come the morning his battery will be dead and needing a jumpstart. The only thing thats been done since he's had it is replaced the radio, all was fine for a few weeks and then this started happening, He's also put the original radio back in and still the same!

Has anyone had the same problem or might know whats causing this? googling leads me to replacing the brake light switch but could it be anything else thats causing the battery to drain and rear brake lights to turn on?

Cheers for any help!!

[ub7rm]

Could be either.  Brake light switch is a commonish problem with VAG's but its an easy fix.  I know people have had issues retrofitting other vag stereos as they are not fully compatible with the older CANBUS interface and keep the system 'awake' all the time which drains the battery.

Try the brake light switch first as it seems the most obvious fault.  If that doesn't work then a bit more investigation might be required for the stereo / CANBUS option.