Brake lights not working.

PurpleTurbo · May 21st, 2021, 15:55

Hi guys,

Today after I thought I had fixed all my brake light issues I have found yet another problem.

When braking only the centre brake light illuminated, it has brand new dual filament bulbs in both corner lights and I have fitted a new brake switch as the car was missing one when I bought it.
When braking the light out warning on the dashboard also comes up.
As far as I can tell the bulb holders are making good contact with the contacts

Any help is much appreciated! TIA.

Rversteeg · May 21st, 2021, 18:33

The NS brake light shares the feed with the center brake light, so it does not seem to be a feeding circuit problem. The breaker switch shoud be all right.
The light out warning compares NS+center and OS, so if only the center ligt is working, it responds to the imbalance.
Are you sure both new bulbs are working, the correct type and correctly fitted?

PurpleTurbo · May 21st, 2021, 21:23

Quote:

Originally Posted by Rversteeg

The NS brake light shares the feed with the center brake light, so it does not seem to be a feeding circuit problem. The breaker switch shoud be all right.
The light out warning compares NS+center and OS, so if only the center ligt is working, it responds to the imbalance.
Are you sure both new bulbs are working, the correct type and correctly fitted?

Theyre the right type, one of them when fitting I couldnt twist it for some reason, however the DRL still works so that would tell me it is still making good enough contact.

Laird Scooby · May 21st, 2021, 22:22

Quote:

Originally Posted by PurpleTurbo

Theyre the right type, one of them when fitting I couldnt twist it for some reason, however the DRL still works so that would tell me it is still making good enough contact.

No, the DRL which is in fact the taillight and should be dimmer than the brake lights works off a different contact on the base of the bulb. Are you sure the brake light filaments are intact and working?

PurpleTurbo · May 22nd, 2021, 00:18

Quote:

Originally Posted by Laird Scooby

No, the DRL which is in fact the taillight and should be dimmer than the brake lights works off a different contact on the base of the bulb. Are you sure the brake light filaments are intact and working?

Okay ive just checked the video I took to check the brake lights, the taillights are the same brightness as the centre brake light wether braking or not.

I dont know much about troubleshooting problems but it seems like the brake lights are on all the time maybe? but then I would think that the bulb out light wouldnt illuminate in that case but clearly I am wrong.

Laird Scooby · May 22nd, 2021, 01:01

Quote:

Originally Posted by PurpleTurbo

Okay ive just checked the video I took to check the brake lights, the taillights are the same brightness as the centre brake light wether braking or not.

I dont know much about troubleshooting problems but it seems like the brake lights are on all the time maybe? but then I would think that the bulb out light wouldnt illuminate in that case but clearly I am wrong.

Pull the brake light fuse or you'll have a flat battery then! The brake lights work regardless on the 7/9xx range.

loki_the_glt · May 22nd, 2021, 08:20

Check the two positive feeds to the lamp-holder: Yellow/Red is the stop light feed, Grey/Black is the tail-lamp feed. They might have been swapped over at some point in the past even though there are coloured stickers on the lamp assembly for the benefit of the hard-of-thinking.

Ian21401 · May 22nd, 2021, 09:58

It appears that the brake light filament (21w) in the bulbs is being fed by the tail light feed which is live when running.
In your post ( #3 ) you mention that you couldn’t twist one of the bulbs. It’s either the wrong bulb or the holder is damaged or you were not putting it in correctly. Stop/Tail bulbs have the pins offset, but you probably know that.
Or, as Loki suggests ( post # 7 ) the wiring is wrong.

PurpleTurbo · May 22nd, 2021, 17:48

Quote:

Originally Posted by Ian21401

It appears that the brake light filament (21w) in the bulbs is being fed by the tail light feed which is live when running.
In your post ( #3 ) you mention that you couldn’t twist one of the bulbs. It’s either the wrong bulb or the holder is damaged or you were not putting it in correctly. Stop/Tail bulbs have the pins offset, but you probably know that.
Or, as Loki suggests ( post # 7 ) the wiring is wrong.

Its the right kind of bulb im almost certain, the holder being damaged would make the most sense to me.

If I flip the connectors around the lights do not illuminate at all.

Laird Scooby · May 22nd, 2021, 17:55

Quote:

Originally Posted by PurpleTurbo

Its the right kind of bulb im almost certain, the holder being damaged would make the most sense to me.

If I flip the connectors around the lights do not illuminate at all.

That doesn't make sense if they are normal bulbs unless a filament is blwon. Do you have a multimeter?

May 21st, 2021, 15:55	#1
PurpleTurbo New Member Last Online: Nov 29th, 2023 16:33 Join Date: Jan 2021 Location: Caithness	Brake lights not working. Hi guys, Today after I thought I had fixed all my brake light issues I have found yet another problem. When braking only the centre brake light illuminated, it has brand new dual filament bulbs in both corner lights and I have fitted a new brake switch as the car was missing one when I bought it. When braking the light out warning on the dashboard also comes up. As far as I can tell the bulb holders are making good contact with the contacts Any help is much appreciated! TIA.

May 21st, 2021, 18:33	#2
Rversteeg Master Member Last Online: Yesterday 16:59 Join Date: Feb 2006 Location: Amersfoort (NL)	New bulbs The NS brake light shares the feed with the center brake light, so it does not seem to be a feeding circuit problem. The breaker switch shoud be all right. The light out warning compares NS+center and OS, so if only the center ligt is working, it responds to the imbalance. Are you sure both new bulbs are working, the correct type and correctly fitted?

May 22nd, 2021, 08:20	#7
loki_the_glt Torquemeister Last Online: Yesterday 08:36 Join Date: Dec 2004 Location: Asgard, Cheshire	Check the two positive feeds to the lamp-holder: Yellow/Red is the stop light feed, Grey/Black is the tail-lamp feed. They might have been swapped over at some point in the past even though there are coloured stickers on the lamp assembly for the benefit of the hard-of-thinking. __________________ loki_the_glt - Skipper of the Exxon Valdez, driver of Sweden's finest sporting saloon - and pining for another Slant-4.

May 22nd, 2021, 09:58	#8
Ian21401 Premier Member Last Online: Feb 11th, 2023 20:32 Join Date: May 2010 Location: Blyth, Northumberland	It appears that the brake light filament (21w) in the bulbs is being fed by the tail light feed which is live when running. In your post ( #3 ) you mention that you couldn’t twist one of the bulbs. It’s either the wrong bulb or the holder is damaged or you were not putting it in correctly. Stop/Tail bulbs have the pins offset, but you probably know that. Or, as Loki suggests ( post # 7 ) the wiring is wrong. __________________ Ian. Since 2005: 1992 Volvo 940 estate 2.0L. Manual. Daily driver and workhorse.

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