A4 Cabriolet high level brake light fix.

[mhobson]

My wife has had the car for 14 years and the high level brake light often stops working, a warning shows on the dash board.

I bought a new unit but it would not work, eventually put the original unit back and got it to work for a while to pass the test.

This has been ongoing eventually I had enough.

The problem I think is the tiny little connector pins in the lamp unit, ridiculously thin, tiny little plug with little option to tighten the contacts.

Fortunately the plug faces upwards towards the pins. To give a better contact to the pins I got some clean copper pipe, ground the end on a fine file and made some copper dust.

I gave a quick squirt of electrical cleaner into the plug and followed it up with the dust.

I then sprayed the plug again to take the dust to the bottom of the holes, making sure that there was no copper remaining so as to cause a short circuit.

Put it back together and IT WORKED!!!

[mhobson]

So, it worked for a while. The issue is the tiny little connections within the plug, even when I fitted a brand new lamp unit it would not work. I know that the LED lights need little current but for the benefit of an adequate contact the pins are just too thin. My copper dust packing lasted for a while, but I think in time it dropped out of the bottom of the plug. What I did in the end was get some multi core electrical cable and take several copper strands from within. For each side of the lamp plug I twisted two lots of two strands together, poked one in each plug hole, to take up a bit of free play, making sure there was none showing at the top which may have caused a short, it was rather fiddly but now the brake light works every time.

[vwroyd]

A good fix that!!!

Mine has started to occasionally flash this warning so this is good to know.

Just a thought, but do you think something like copper grease or similar would work?

[mhobson]

It may work, but I don't know how much copper is in the grease, would the grease reduce connectivity and if it did not work, how difficult would it be to make the interior of the plug clean again. Since my last repair the high level brake warning has never turned on.