MK5 Golf GTI

All Things Mk5 => How to Guides / Troubleshooting => Topic started by: vinceUK on March 09, 2025, 01:52:58 pm

Title: Third brake light always on
Post by: vinceUK on March 09, 2025, 01:52:58 pm

Hi all,

The third brake light of my 2008 Golf mk5 TSI is constantly ON despite the ignition being OFF (not on the accessory position) and the brake pedal not pressed. The other rear brake lights remain OFF as expected and they work correctly when the ignition is ON. I have to remove the related fuse from the engine fuse box to turn it OFF so it won't drain my battery.

I've noticed that water was sometimes leaking from the boot trim after a rainy day so I am wondering if this could have damaged the third light circuitry somehow.

Has anyone already experienced this issue? How should I investigate it?

Thanks,
Vince

Title: Re: Third brake light always on
Post by: mjmallia on March 10, 2025, 08:58:35 am

Wires in the tailgate loom are most probably broken and arcing

Title: Re: Third brake light always on
Post by: Octoparrot on March 10, 2025, 01:10:51 pm

Quote from: mjmallia on March 10, 2025, 08:58:35 am

Wires in the tailgate loom are most probably broken and arcing

Yes this would be my first port of call.