Rear brake light failure -help

[dan_b]

Ok, I should have re-sealed my rear light cluster, this was bound to happen...

On Friday, my right rear light cluster gave up. Autocheck had a hernia trying to tell me that my brake lights weren't working, and the indicators were on double time.

Left rear cluster works fine. Left front lights ok, but my right front side light is also not working.

I replaced all the bulbs at the rear, and have replaced the bulb holder.

Things are all working now when the headlights are off, BUT. When I turn the headlights on, Autocheck goes bonkers, and the right rear brake/tail light refuses to work.

Help please - what wiring should I be looking out for? I presume there is something connected with teh front right sidelight going out as well?

[s2avant]

It sounds like you have a short between the taillight and brake light terminals in the bulb holder. When you turn the headlights on it back feeds through the brake light circuit. Check to see if the headlight or sidelight comes on when you brake with the head lights turned off.

Check you haven't got a single filament lamp in place of the stop/tail lamp. Sounds simple but I'm sure a lot of people have done this in their past.

If not check that the stop/tail lamp is fitted correctly. If you get it offset you can cause a short between the tail lights and the brake lights.

HTH,

Ben

[Stick Insect]

Check you haven't got a single filament lamp in place of the stop/tail lamp. Sounds simple but I'm sure a lot of people have done this in their past.

If not check that the stop/tail lamp is fitted correctly. If you get it offset you can cause a short between the tail lights and the brake lights.

HTH,

Ben[/QUOTE]

There were some crap bulbs about a couple of years ago, the brake light (dual filament) ones had a fault, when they got hot the top filament drooped down onto the lower filament. this meant that when you braked your sidelights came on. Someone who was a very cautious driver used to cover the brakes when he approcahed a road junction if someone was waiting at it. Because the brake light was lit, it made his side lights come on. This was taken as a signal by the person at the junction and they pulled out!

This freaked him out and he had a few near misses.

I feel that you have got some short circuit between the circuit strips, clean them thoroughly and then use silicone grease on the connections.

I thought it was coupes which were meant to leak!

David

[dan_b]

Looks like one of the bulbs I bought was blown Off to get a replacement...
How do you get the front right side light bulb out?

[Stick Insect]

Looks like one of the bulbs I bought was blown Off to get a replacement...
How do you get the front right side light bulb out?

Dan,

on mine ( different engine)

Open the bonnet, push and slide down the spring clip holding the black circular cover on the rear of the headlamp. This will then allow you to gain access to a small ( 5 w?) bulb. Thinking as I type the S2 has sidelights where Audi 80's have indicators? there must be a waterproof access panel. The UK nearside is average to get at. the O/s is probably awful as the turbo is in the way! wait for the turbo to cool down first!

Have fun.

David

[dan_b]

replaced bulb, same result- brake light works but when switch headlights on, Autocheck has a spasm. Further investigation required.

There are three big black circular bulb holders for the headlight cluster, but no apparent way of removing the right-hand-most one? Does it turn and pull out?

Access to right one is easier for me now I removed the airbox and associated gubbins!

[dan_b]

replaced bulb, same result- brake light works but when switch headlights on, Autocheck has a spasm. Further investigation required.

There are three big black circular bulb holders for the headlight cluster, but no apparent way of removing the right-hand-most one? Does it turn and pull out?

Access to right one is easier for me now I removed the airbox and associated gubbins!

[Stick Insect]

[QUOTE=dan_b] There are three big black circular bulb holders for the headlight cluster, but no apparent way of removing the right-hand-most one? Does it turn and pull out?
QUOTE]
Dan, my lights are different, I would imagine it is a bayonet fitting twist and remove.

David

[dan_b]

Got front side light out, it was one of those bayonet jobbies: replaced bulb, that front side light is still not working, and the rear brake light/tail light doesn't work when you have the headlamps on.
Autocheck is happy with the rear brake lights without headlights on.

What's going on?

[Stick Insect]

Got front side light out, it was one of those bayonet jobbies: replaced bulb, that front side light is still not working, and the rear brake light/tail light doesn't work when you have the headlamps on.
Autocheck is happy with the rear brake lights without headlights on.

What's going on?

Look at the fuses Dan, there is probably one for the RHS ( sidelights) of the car, check and replace if faulty.

HTH

David

[dan_b]

Any idea which fuse will be which, or is it just a random hunt?

[A6 AVANT]

Dan, just a question...... I know you have checked lights,fuses etc. but have you got a tow bar fitted? If so, might be worth a check of connections/plug etc. You say autocheck has spasm when "headlights" are on does this also happen when sidelights are on? Fault does sound like a faulty bulb or single filament bulb in a stop and tail fitment. using a circuit tester, check for lives and earths on rear cluster with someone operating switches bit be careful not to short out fuse when poking tester into the bulb holder. Shame you are not in my area, I would have been more than happy to have a look.
Regards
Chris

[dan_b]

A fair question, but no I don't have a towing bar attached...
Autocheck spasm - I didn't check if that happened only on sidelights, will do so. I'll check the fuses tomrrow when it's light again. Might have to get myself a circuit tester!

Thanks for all the input so far guys!

[Stick Insect]

Any idea which fuse will be which, or is it just a random hunt?

Dan,

On mine it is fuse F6 ( 5 amp) It is written on the fuse box lid. There should be a spare fuse under the cover.

HTH

David

[martinjs]

Dan check the connector on the rear cluster that is on its own next to the multi plug, this caused loads of problems for me when i first got my car.

martin