Brake lights

Nine40 · Mar 5th, 2019, 14:21

Both rear brake lights dont work and bulb failure lights up, changed bulbs and cleaned contacts the high level brake light works..tail lights still work and bulbs are correct ones. what should i look at next?
Its an automatic.

Cheers

TonyS9 · Mar 5th, 2019, 15:02

Measure the voltage on the wire with the brake pressed.

Make sure the earth is good, and all the connections obviously. Have you the bulb holder in correctly and making good contact?

Is the bulb contacting all 3 connections properly?

Try wedging a brush between the seat and the brake pedal then checking the above.

loki_the_glt · Mar 5th, 2019, 15:09

Take out the lampholders and inspect them for pitting/lack of contact with the power or earth track. Sometimes the plates cease making contact and the main stop lamps fail and removing them and GENTLY bending the contacts back will re-make the circuit.

While you've got them out of the lampholders check the bulbs by connecting them direct to the battery.

Possibility no.3 is that the spade connector from the loom has become dislodged on one side. The bulb failure works on a current differential between the two main stop lamps and if one side stops working it will trigger the warning lamp.

Nine40 · Mar 5th, 2019, 15:10

Tried that but still not working, if it was the switch the third light wouldnt work eould it?

loki_the_glt · Mar 5th, 2019, 15:17

Quote:

Originally Posted by Nine40

Tried that but still not working, if it was the switch the third light wouldnt work eould it?

You're correct - the High-level lamp is in the same circuit, so you can effectively eliminate the brake switch as the problem.

As the stop lamps are permanently live you can check by backing up to mirror if you haven't got an assistant to operate the brake pedal for you while you observe. With the engine switched off you'll also eliminate the possible confusion of the taillamps (Been there, done that).

Nine40 · Mar 5th, 2019, 15:42

Could it be the bulb failure relay? Ive remived and inspected the lights and cleaned the contacts and bent the pins slightly so they are goid fit.. still nothing 🥴..bit strange both sides are off.

Laird Scooby · Mar 5th, 2019, 19:46

Renew all 3 brake light bulbs with brand new bulbs of the same make.

jpliddy · Mar 5th, 2019, 20:43

hi i changed my clear bulbs to to red ones they are much rider now in my fading rear lens now as they get weaker the M.O.T man will spot they rant red enough mine were like candles before i changed them to red ones

Ian21401 · Mar 5th, 2019, 20:52

Agree with Dave re replacing all bulbs, at least the two standard ones. Re the bulb failure warning: I have towing electrics fitted ( twin 12N. & 12S )
The trailer lights are linked to the car’s wiring via a 7 way relay which senses the current in the car’s wiring and switches on the required trailer lights. Very occasionally the bulb failure warning pops up immediately after starting the engine. A quick dab on the brake pedal to activate the brake lights extinguishes it. First time it happened I checked the brake lights and they were ok. Don’t know the reason but suspect it’s something to do with the relay.

lionheart002 · Mar 5th, 2019, 21:15

Just bridge the plug with the switch disconnected. If they work, get a new switch.

Mar 5th, 2019, 14:21	#1
Nine40 Senior Member Last Online: Dec 10th, 2020 23:04 Join Date: Feb 2019 Location: Blackpool	Brake lights Both rear brake lights dont work and bulb failure lights up, changed bulbs and cleaned contacts the high level brake light works..tail lights still work and bulbs are correct ones. what should i look at next? Its an automatic. Cheers Last edited by Nine40; Mar 5th, 2019 at 14:49.

Mar 5th, 2019, 15:02	#2
TonyS9 Premier Member Last Online: Apr 9th, 2024 21:44 Join Date: Jul 2009 Location: Holywood	Measure the voltage on the wire with the brake pressed. Make sure the earth is good, and all the connections obviously. Have you the bulb holder in correctly and making good contact? Is the bulb contacting all 3 connections properly? Try wedging a brush between the seat and the brake pedal then checking the above. Last edited by TonyS9; Mar 5th, 2019 at 15:05.

Mar 5th, 2019, 15:09	#3
loki_the_glt Torquemeister Last Online: Today 08:32 Join Date: Dec 2004 Location: Asgard, Cheshire	Take out the lampholders and inspect them for pitting/lack of contact with the power or earth track. Sometimes the plates cease making contact and the main stop lamps fail and removing them and GENTLY bending the contacts back will re-make the circuit. While you've got them out of the lampholders check the bulbs by connecting them direct to the battery. Possibility no.3 is that the spade connector from the loom has become dislodged on one side. The bulb failure works on a current differential between the two main stop lamps and if one side stops working it will trigger the warning lamp. __________________ loki_the_glt - Skipper of the Exxon Valdez, driver of Sweden's finest sporting saloon - and pining for another Slant-4.

Mar 5th, 2019, 15:42	#6
Nine40 Senior Member Last Online: Dec 10th, 2020 23:04 Join Date: Feb 2019 Location: Blackpool	Could it be the bulb failure relay? Ive remived and inspected the lights and cleaned the contacts and bent the pins slightly so they are goid fit.. still nothing 🥴..bit strange both sides are off. Last edited by Nine40; Mar 5th, 2019 at 15:46.

Mar 5th, 2019, 19:46	#7
Laird Scooby Premier Member Last Online: Today 15:08 Join Date: May 2012 Location: Lakenheath	Renew all 3 brake light bulbs with brand new bulbs of the same make. __________________ Cheers Dave Next Door to Top-Gun with a Honda CR-V & S Type Jag Volvo gone but not forgotten........

Mar 5th, 2019, 15:10	#4
Nine40 Senior Member Last Online: Dec 10th, 2020 23:04 Join Date: Feb 2019 Location: Blackpool	Tried that but still not working, if it was the switch the third light wouldnt work eould it?

Mar 5th, 2019, 20:43	#8
jpliddy VOC Member Last Online: Feb 15th, 2024 17:04 Join Date: Dec 2006 Location: stoke on trent	brake lights hi i changed my clear bulbs to to red ones they are much rider now in my fading rear lens now as they get weaker the M.O.T man will spot they rant red enough mine were like candles before i changed them to red ones

Mar 5th, 2019, 20:52	#9
Ian21401 Premier Member Last Online: Feb 11th, 2023 20:32 Join Date: May 2010 Location: Blyth, Northumberland	Agree with Dave re replacing all bulbs, at least the two standard ones. Re the bulb failure warning: I have towing electrics fitted ( twin 12N. & 12S ) The trailer lights are linked to the car’s wiring via a 7 way relay which senses the current in the car’s wiring and switches on the required trailer lights. Very occasionally the bulb failure warning pops up immediately after starting the engine. A quick dab on the brake pedal to activate the brake lights extinguishes it. First time it happened I checked the brake lights and they were ok. Don’t know the reason but suspect it’s something to do with the relay.

Mar 5th, 2019, 21:15	#10
lionheart002 New Member Last Online: May 20th, 2019 06:24 Join Date: Jan 2012 Location: Portsmouth	Just bridge the plug with the switch disconnected. If they work, get a new switch.

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