brake lights not working?

[bussell]

Hi all, mot sure if anyone out there might be able to help. I have just picked up my new (old) BX and have noticed that the brake lights do not work.

i have ruled out the switch and bulbs and eventually put a test meter on the wires going to the brake switch and there is no current - all the fuses loom fine???

i am a bit confused,

if you have any ideas of where I cam check next i would be very grateful

It is a 1990 TZD Turbo

thanks

Ed

[David]

Do the: electric windows, green dash back lights, sunroof, map reading lights & wipers work? If not its a fuse in the fusebox (I can't remember which one). (The fusebox is under the dash on the left side). Also if you send 12V live to the (input) side of the brake light switch, do they come on like they should?

There are 3 circuits in the ignition (4 including the starter) The brake lights (& items mentioned above) are on No2. The reversing lights, Rev counter, dip dim control, fan relay & ignition are on No3 & the instrument panel, indicators, heater are on No1

If the rest of the circuit is fine & the above mentioned items work it will probably be a broken wire.
You can use a temporary repair by getting power from something & putting it to the input side of the brake switch.
Someone else might be able to help more than me if it is a broken wire, As I don't know where it goes.

Hope that helps.

[Thread Bear]

Has it had a tow hitch removed? Might be a poor reconnection.

[bussell]

Do the: electric windows, green dash back lights, sunroof, map reading lights & wipers work? If not its a fuse in the fusebox (I can't remember which one). (The fusebox is under the dash on the left side). Also if you send 12V live to the (input) side of the brake light switch, do they come on like they should?

There are 3 circuits in the ignition (4 including the starter) The brake lights (& items mentioned above) are on No2. The reversing lights, Rev counter, dip dim control, fan relay & ignition are on No3 & the instrument panel, indicators, heater are on No1

If the rest of the circuit is fine & the above mentioned items work it will probably be a broken wire.
You can use a temporary repair by getting power from something & putting it to the input side of the brake switch.
Someone else might be able to help more than me if it is a broken wire, As I don't know where it goes.

Hope that helps.

Thanks for the information - I will try running a power supply direct to the switch to see if that helps out. There is already another live feed coming in for the aftermarket indicator relay so I will piggyback off that one to avoid disturbing anything else factory and see how I get on.

Cheers Ed

[citsncycles]

If a new feed doesn't cure it check the connections into the (from memory) LH rear light cluster - I've had issues with the connector from the loom in the past.

[mat_fenwick]

You're correct Mike, it is the LH side. There is a 7 way connector into the LH side, and the RH side is actually fed from a separate connection out of the LH unit! So a problem there could affect both sides.

[bussell]

Thanks for that, I had a look under the l/h light and there are a lot of wires there due to the tow bar electrics - the bulb holder has been repaired in the past where the feed comes in and out to the other cluster - I think someone has re soldered some of the circuit board where it had corroded/melted in the past. They have then covered it with some kind of orange goop (it looks like amber??)

I will try and get another bulb holder as this is less than ideal even if it is not the problem -

I will update when I have a chance to look at this later on -

[Thread Bear]

Hey ho. Tow hitchs and rear light reliability. Should be able to gain a light backplate. Its worth cleaning out the flat loom connectors while your waiting. If the loom wires are messed might be worth picking up at least the across the back one. I am looking at doing a front to back, looks a sod.

[Tinkley]

The correct tow hitch electrics ie Citroen fitted ones, use a brown plastic connector for the ancillary feed. I have re mounted my original tow bar and electrics twice now with no problems at all. Usually it is the tow connector end!. The standard factory BX accepts the plastic connector straight into a slave socket on l/h side rear as none of the two other cars I fitted it to had a tow hitch before but I had no problems at all. The loom going to the tow bar does interfere with getting the rear carpet to sit down tight but otherwise is OK.

Of course if someone used those blue clip in connectors instead......

[bussell]

The correct tow hitch electrics ie Citroen fitted ones, use a brown plastic connector for the ancillary feed. I have re mounted my original tow bar and electrics twice now with no problems at all. Usually it is the tow connector end!. The standard factory BX accepts the plastic connector straight into a slave socket on l/h side rear as none of the two other cars I fitted it to had a tow hitch before but I had no problems at all. The loom going to the tow bar does interfere with getting the rear carpet to sit down tight but otherwise is OK.

Of course if someone used those blue clip in connectors instead......

I think it is citroen fitted bar, no blue clips - I learned that lesson on my old Picasso - she really didn't like the towbar wiring using the blue clips and all sorts of light issues followed - including bizarrely a reduction in the voltage going to the front sidelights which had to be converted to LED - Ended up removing them all and doing it properly

[Tinkley]

The actual towbar (oe Citroen fitted one) is a substantial thing with two large diameter tubes about 45mm diameter. Maybe a bit of corrosion somewhere, definitely check the earth point as any bad earth will give problems. The two sides are linked so if one works the other should too, unless a bulb has gone. I can't remember offhand, but one side, I think the left does have an earth stud and nut.

[bussell]

The actual towbar (oe Citroen fitted one) is a substantial thing with two large diameter tubes about 45mm diameter. Maybe a bit of corrosion somewhere, definitely check the earth point as any bad earth will give problems. The two sides are linked so if one works the other should too, unless a bulb has gone. I can't remember offhand, but one side, I think the left does have an earth stud and nut.

Hi, yes it is an OE by your description - and the wiring plugs directly into the back of the left hand light and despite there being lots of wires in behind the light unit it is neat and tidy.

I'm pretty sure that the main feed from the fusebox has failed as I have double checked with my multi-meter at the brake pedal switch and there is no power coming through - this weekend I will put a fuse on the permanent feed to the after market indicator relay (which it is lacking right now and comes direct from the battery!) and will check the system with power in it.

[Pallas]

Brakelight switch and ignition switch are one of the most common faults if both the lights don't work!
I run my brakelights over a relay with an antiparallel diode. The switch operates only the relay - no problems since even when pulling trailers!

[bussell]

Hi all, thanks for your advice - it really helped me get brake lights working again - the earth behind the left cluster was cleaned - still no brake lights - then I cleaned the connector from the loom to the bulb holder and success! - all rear lights working.

Plus I fitted a new light/indicator switch and I have main beam now.

All lights except fog lights now working!