Can a failed brake light kill the other lights and the brake light switch?



The VW dealer replace the brake light switch on my 2001 Golf TDI (diesel) with manual transmission as part of a safety recall. Within 1,000 miles (about 1 month of driving), the new switch and all of three brake lights (2 tail lights and center LCD light on back window) were dead. The technician at the VW dealer told me that one of the brake lights in the tail light had shorted (yes, he said it shorted – he said that the filament was missing, but there was still connectivity in the light). He then said that this shorted light bulb “killed” the other lights and the brake light switch. Based on this scenario, the problem was my bad luck and they charged me for the entire repair. It seems pretty curious to me that the failures occurred soon after the brake light was replaced. I suspect that the new switch failed and this is what killed the three brake lights. I have the light bulbs from both tail lights and I can’t measure any connectivity in either one. Even if a light bulb could short, could it kill all the other parts of the circuit (other bulbs and the switch)? If a light bulb shorted, why wouldn’t the fuse protect the circuit? If a failed brake light killed the brake lights, how could this be proved? What responsibility does VW have to fix the brake lights if the new switch made them fail? I feel like I was taken advantage of!


I don’t see any way for a shorted out bulb to cause the other bulbs and switch to fail. On the other hand, I can’t think of any good reason the switch would have caused this either. The switch is either on or off, if it’s bad it will probably be permanently off, and rarely permanently on. In the latter case the bulbs might go bad from being on all the time, but I’d think you would have noticed.

Sounds like some random bad luck to me, unless they miswired something when they replaced the first switch, and you’ll never prove that if they fixed it already.


No, I don’t buy this explanation but neither do I accept the mechanic’s version as a tre and valid description of events.

He finds bad bulbs and a bad switch. He has no clue what happened nor why. He makes the repairs (replace everything) and reports a story to the customer. He’s not dishonest – that’s all he can do. Likely we will never know what caused everything to go kerblooey.


Shorted lamp, and I have never seen a shorted lamp, should open the fuse. I wonder if there was an electronic module involved that may have blown. That is needed for some cars to separate the brake light (3 filaments) or turn function (one filament) Why they would not tell you this is a question.