Third Brake Light

[andrewswinson]

I have a roof spoiler / third brake light on my car which has not worked during my ownership. I have connected a separate 12 volt supply to the lamp and it works, so I guess there is a problem with the feed from the car.

Does any know where / how these things are connected into the loom? From the lamp, the feed enters into the car through the window seal (top centre of window) and then goes right to the offside of the car. The cables are embedded in mastic, so it is difficult to trace them.

Thanks for any advice.

Andrew

 

[38F3E1]

There is a detailed explanation of a common cause of this and a fix for it on www.p-car.com in the DIY section called "How to repair 3rd tail light broken wiring". At least it will help you work out if this is your problem.

 

[andrewswinson]

Finally got round to sorting this out.

The p-car fix got me excited (as a simple solution[]), but alas I had no power on the inside of the glass.

As the live supply was dead, I resolved the problem by removing the rear parcel shelf, disconnecting the brake light feed from the rear window (centre connection of 3 - heated rear window, brake light and earth) and ran a new wire up to the third rear light connection, tucked inside the window rubber. I swapped the (old for new) feeds on the soldered connection and all works.

I guess there was a break in the original feed between the bottom and top of the glass.