Stubborn lack of brake lights!

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mnde
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Stubborn lack of brake lights!

Post by mnde » Tue Nov 07, 2006 10:10 pm

Dear BX'ers,

I've trawled through the archive, but haven't found an answer to this electrical gremlin... My brake-lights have failed and I can't find out the cause! I've checked:

1) Switch connection at brake pedal
2) I've tested both stoplight bulbs, and all the others in the rear clusters work fine.
3) I've taken apart all the connectors behind the clusters and WD'd them, and I cleaned and WD'd the stoplight bulb terminals, and also squirted the body earthing points.
4) Fuse #3... well, everything else covered by this fuse works fine, except the rear demist which seems to have become somewhat less effective... ohh hmm I forgot the sunroof has packed in too (won't open) - and the BOL tells me this is also on fuse #3 - could be linked....?

In the meantime the GSA has come to the rescue (hurrah!) but I was hoping to fix the BX tonight.... grr! hate rooting around with a torch on winter's nights trying to trace electrical faults without a helper... Thoughts anyone?

Cheers,

Mark.
1982 Citroen GSA Spécial Estate
1997 Renault Mégane RT 1.4e
1991 Citroen BX16 TGS Meteor - gone to Scotland

jeremy
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Post by jeremy » Tue Nov 07, 2006 10:22 pm

Have you shorted the 2 wires on the brakelight switch together? I had the switch fail - cleaned it once with switch cleaner - OK - then went again (while I was on holiday) - and it wouldn't work reliably and I had to replace it.

Its fun trying to get it in! - Old Mini ones screwed into a threaded boss - this one goes through a hole and you have to get a nut on the other side!

New switch was a Citroen part - cost less than £5.

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mnde
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Post by mnde » Tue Nov 07, 2006 11:12 pm

Ah thanks Jeremy, no I didn't try that! Only took the spade connectors off and pushed them on again. Will have another go tomorrow.

Cheers,

Mark.
1982 Citroen GSA Spécial Estate
1997 Renault Mégane RT 1.4e
1991 Citroen BX16 TGS Meteor - gone to Scotland

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thanuttiscotsman
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Post by thanuttiscotsman » Wed Nov 08, 2006 12:05 am

hi there,
i have the exact same problem with my 16v gti. ive cleaned all connectors earths etc. i have also tried a new switch (took one out my 1.4 bx before i burned it) and that didnt work. but the 1.4 brake lights did. i find when putting a test bulb between the switch wires light goes on but when i try the same with the ign on the bulb goes off. very strange indeed. try using a test bulb to see if you get anything if not i have a spare switch if you need it.

rossco
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Post by Brian » Wed Nov 08, 2006 12:18 am

Hi,
If after all the tests and checks fail to pin point the problem.

Could be that the flat multi cable has fractured.

If so, just run 2 more wires from the stop switch to the rear lights.

Had this problem some years back, and that fixed it ...

Good luck

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sleepy0905
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Post by sleepy0905 » Wed Nov 08, 2006 8:54 am

Had this problem and it was the stop switch at the peddle that had failed if you are carefull you can take the switch apart and clean the contacts its usually the feed side contact that gets all blackened and pitted I have just repaired this same fault on my neighbours saxo which had the same problem I have a working switch here somewhere if you need one.
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Kitch
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Post by Kitch » Wed Nov 08, 2006 4:51 pm

Is it possible the switch itself is duff? Bridge the wires together and see what happens?

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Way2go
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Post by Way2go » Wed Nov 08, 2006 5:11 pm

Kitch wrote:Is it possible the switch itself is duff? Bridge the wires together and see what happens?
Good starting point. Then if unsuccessful make up some longer leads for the multimeter with croc clips on the end (for ease) and trace through to the rear.
1991 BX19GTi Auto

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mnde
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Post by mnde » Wed Nov 08, 2006 11:09 pm

Thanks people!

Well whaddaya know: I bridged the two connector wires to the switch and hey presto, the stop-lights came on. But only when the ignition was on... I thought the stoplights usually came on even if you pressed the pedal with the ignition off - they do on the GSA...

Ah well, anyway I seem to have found the cause, although I think I'm going to entrust the job to the Citroen specialist, as I was going to book it in for a service anyway. It looks a bugger to get off/on, especially in the dark with a torch, and I have a v busy weekend.

The sunroof was just stuck, I found. A couple of twists with the manual winder and it's now back in action.

Cheers,

Mark.
1982 Citroen GSA Spécial Estate
1997 Renault Mégane RT 1.4e
1991 Citroen BX16 TGS Meteor - gone to Scotland

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Post by jeremy » Wed Nov 08, 2006 11:45 pm

I'm sure ZX is the same - ie works when the ignition is on. In fact this switch also turns the ABS from monitor to active mode as well.

Its not that difficult - just awkward to get everything in the right position without damaging your fingers - calssic case of needing 3 hands - but its too difficult for someone to assist.

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Way2go
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Post by Way2go » Thu Nov 09, 2006 4:30 am

mnde wrote:Well whaddaya know: I bridged the two connector wires to the switch and hey presto, the stop-lights came on.
Another plan comes together. :D
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Stewart (oily!)
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Post by Stewart (oily!) » Thu Nov 09, 2006 10:13 am

If you remove the under panel on the steering column the brake light switch is very easy to replace.
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mnde
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Post by mnde » Thu Nov 09, 2006 10:27 am

Do I need two spanners on it? It looks to have a nut infront of the mounting bracket as well as behind. I admit in the cold and dark last night I couldn't be bothered to get the spanner set out. Also I'm slightly wary of working on my car half on the pavement in the dark with the torch. I don't want to be reported to the police by a suspicious someone who thinks I'm breaking into and trying to hotwire a car!

Mark.
1982 Citroen GSA Spécial Estate
1997 Renault Mégane RT 1.4e
1991 Citroen BX16 TGS Meteor - gone to Scotland

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Post by jeremy » Thu Nov 09, 2006 10:38 am

You can in fact probably loosen one of the nuts and work the far one off with your fingers. The only problem is getting the nut on the new one, which needs the pedal to be held down while its slipped in the gap.

Might as well do it in the dark - you won't see much by daylight!

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Kitch
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Post by Kitch » Thu Nov 09, 2006 4:06 pm

Piece of piss to replace it mate. I use pilers to undo the retaining nut, they don't need to be silly tight.

But the brake lights should only come on with the ignition. I've never seen a car that has them wired up all the time.