Failed Brake Lights

Ratbags. This is a serious one. Trust me - I won't be using the car again until it's sorted!

Here's what I've done so far:

Cleaned and tested the rear lamp clusters (because I've had intermittent failures on one side before, and that always helped temporarily), then figured out which connection on the connector block is which and discovered zero volts being delivered to the brake lights on both sides.

Checked the fuse - OK. Checked that there was power at the fusebox - yes.

Took apart the brake pedal to test the switch. There are 12 volts at the switch, and according to the multimeter the switch works.

So what the hell is after the switch that's causing the problem?

I don't have a Haynes manual but I called a friend who does. He had a look at the wiring diagram, and it seems that the lamp failure module is between the switch and the lamps. Looks like that might be our culprit!

So... where is it, physically, in the car? Are they known to fail in this way? Can it be taken apart, cleaned, fixed? Or am I looking at a new one? Are the available?

Thanks for any advice!

I believe the box is blue in colour and located behind the dash on the drivers side, somewhere around or above the parking brake release handle.

This post has been edited by Ciaran on January 13, 2008 02:50 am

I was hoping to get through this without those three words being uttered

Oh well. My left-hand heater doesn't work and I've got a few bulbs out so it will be a worthwhile job.

Someone was talking about it not so long ago, believe it might have been Peter and Rowan, but I can't find the thread unfortunately.

Favourite are the wires that go from the main body to the tailgate. The continual opening and closing bends the wires and they eventually break. You can pull the grommet/gaiter out of te body with a bit of effort, inspect the wires and you will likely find one or more broken. Dont be tempted to join it where the break is or it will go again, but pull the wire out as far as it will come and join about 6" of wire onto it then poke it back throught the hole and join the other end so that the join is not where it flexes.

Peter.N.

100% agree that the highest probability is that the wire in the tailgate/hatch lid through the corrugated rubber tube is the first place to look for trouble in the rear end. Usually the RH one is where the fault lies.
This applies to fogs, rear window heater, screen wiper and washer etc.

The brake lights are in the body of the car, not the tailgate - does wiring for them run through the tailgate? Why?

I don't think it does....it couldn't...could it?
This is a Citroen mind you.

I'll be following this thread with interest, I'm getting persistent failure of the left hand brake light now despite a new bulb and cleanup etc, think it might be a wiring job....

Ciarán

Sorry, I'm getting confused It's practically all the other lights that run that way. It was my reversing lights that packed up.

Peter.N.

there are duplicate brake lights in the tailgate, one of the things i liked about XM's back when I was first thinking of getting one (back when backup brake lights were rare).

I believe the second set of red lights in the tailgate are actually extra tail lights, rather than brake ones.

Ciarán

whoops displaying my ignorance again.

You're sort of both right!

The lamp cluster on the body contains the indicator, a twin-filament bulb that is both tail-lamp and stop-lamp, and another stoplamp.

the tailgate contains reversing lights, a second set of tail-lamps, and the foglamps.

So yes, there is a lot of redundancy in the case of bulb failure which is a good thing.

But my car is showing no brake lamps at all

This post has been edited by stu on January 14, 2008 02:18 pm

Have you got an auto dipping n/s mirror worked by the reversing switch? if so does it work?

Peter.N.

Nope, don't have one. It's a boggo 2.0I, it doesn't have much at all! I like it that way - there's less to go wrong.