Brake lights problem

[ollie_joe]

its a 2001/2002 A3. Sorry for the late reply had some other issues to deal with regarding my ECM light.

still having the intermittent problem with the brake light. Sprayed some electrical spray over the light connections in the light box and that seemed to do the trick for about a week or so.

Problem is less frequent now, but still crops up from time to time and am concerned it will fail MOT.

[Crasher]

Have you tried a new bulb?

[ollie_joe]

Yes have tried a new bulb and no joy.

Do you know if it is possible to get hold of a new light box? as i think that is where the problem lies.

[Crasher]

The bulb holder for a 2001 A3 is 8L0 945 257 A for either side and costs £13.

[ed'sA3-1.8THK]

take 5 minutes and use light to inspect brake pedal/brake light switch (try to look w/o removing knee panel)

if switch is "black" colour it is (1) of (3) earlier revisions - if switch is "green casing" (or possibly "blue casing") you already have latest part revision - elec contacts have been burning away and/or welding together on all earlier switch revisions

check also (3) main earth/ground points (1) small & large threaded studs under battery - (2) under right side instrument cluster on inside firewall threaded stud - (3) rear of car (fuel pump & light & cd player/sound system threaded stud

clean all brass earth/ground rings/lugs & chassis surface - do not over tighten nut(s)

finally, have you diy / added back-up alarm & connected to reverse lights circuit and accidently shorted to stop light circuit?

factory internal service bulletin instructs all audi service depots/dept's to clean the (3) main earth points when cars brought in for routine servicing AND to replace cabling under battery if serious corrosion is found...

[ollie_joe]

Many thanks

will order today hopefully that will fix the problem.

Will let you know.

Cheers

Ollie

[Porcorosso]

There are a number of instances of the rear light board failing in older cars. Your A3 is a 90s design and its possible the actual board has failed. I've had this happen on a Ford and a Fiat that i have previously owned.

Perhaps this is what has happened to yours.

[ollie_joe]

Replaced the light casing over the weekend. Problem has gone away for the time being, even managed to pass the MOT. So pleased for know.

Thanks for all your helpful comments.

Now just need to get the boot light working again ...