Brake lights not working, 3rd top light is.

[Upia]

Hi all, I’ve had a good search around but couldn’t find any threads with the same issue that was resolved.

I’ve noticed my rear brake lights don’t work, the bulbs are fine, the fuse is fine and the wiring doesn’t appear to be damaged where it’s visible.

I’ve ordered a brake switch and intend to change that, however would the top tail light still work with a dodgy brake switch?
if it turns out to not be the switch, what are the likely culprits?
Car is a 2005 FR 1.8t AUQ if that makes any difference.
Thanks.

 

[RADIOTWO]

Hi all, I’ve had a good search around but couldn’t find any threads with the same issue that was resolved.

I’ve noticed my rear brake lights don’t work, the bulbs are fine, the fuse is fine and the wiring doesn’t appear to be damaged where it’s visible.

I’ve ordered a brake switch and intend to change that, however would the top tail light still work with a dodgy brake switch?
if it turns out to not be the switch, what are the likely culprits?
Car is a 2005 FR 1.8t AUQ if that makes any difference.
Thanks.

If the top brake light works its not the switch which leaves its the bulbs, bulb holder or earth. You say the bulbs are fine but how do yo know ? have you checked for voltage at the holders ??

 

[Upia]

I bought a new pair of bulbs but also swapped the fog light bulbs over, the brake light bulbs illuminate as fog lights.

I haven’t checked voltage as I can’t measure the socket and press the pedal.
is the earth in the boot under the lining somewhere?

 

[RADIOTWO]

I bought a new pair of bulbs but also swapped the fog light bulbs over, the brake light bulbs illuminate as fog lights.

I haven’t checked voltage as I can’t measure the socket and press the pedal.
is the earth in the boot under the lining somewhere?

Where about's in the County do you live ?

 

[Upia]

I’m in South Derbyshire, near Burton upon Trent.

Edit: I see you are Derbyshire too, I’m Swadlincote specifically, but Derbyshire is pretty big lol.

 

[RADIOTWO]

I’m in South Derbyshire, near Burton upon Trent.

Edit: I see you are Derbyshire too, I’m Swadlincote specifically, but Derbyshire is pretty big lol.

Yes thats a shame I am in the north of the county, I was going to suggest I could help you, but as you say a big county, but if you have a multi meter just get someone to press the break pedal while you check the voltage

 

[Upia]

Yes thats a shame I am in the north of the county, I was going to suggest I could help you, but as you say a big county, but if you have a multi meter just get someone to press the break pedal while you check the voltage

Well thanks for the thought anyway, I’ll see if I can get a mate to help sometime this week.
I’ll update the thread if I get it sorted, nothing worse than looking over threads of problems that are years old and there’s no solution.

 

[iammooks]

I’ll update the thread if I get it sorted, nothing worse than looking over threads of problems that are years old and there’s no solution.

Doing the lord's work there.


Sent from my iPhone using Tapatalk

 

[smutts]

My ASV diesel shows the engine fault light when both rear bulbs are blown, but with the central LED working.
I assume the computer dribbles a tiny bit of electricity into the supply wire, to sense if the bulbs are there or not. That is why fitting LED bulbs as brake lights can be bit of a faff, as you will need to solder in a 1000 ohm resistor to make the computer think the bulbs are "there".

Ok, it just seems to me that if either the loom, bulbs, earths etc are bad, that there should also be a warning light on the dash.
Your AUQ might do things differently.

 

[Upia]

Ah I’ll have to scan later today and see! My engine light is constantly on due to the SAI being iffy, so I wouldn’t know if it’s also throwing up something to do with lights.
speaking of LEDs, I do have led tail lights but not brake lights, I wonder if that is also messing with it? Something else I’ll check later too.

 

[Upia]

So today whilst in the dark I noticed my passenger sidelight come on whilst pressing the brake pedal.
Could this be an issue with the CCM all along?
Is there a specific part number for Seat or are they interchangeable from VW/Skoda etc

 

[RADIOTWO]

So today whilst in the dark I noticed my passenger sidelight come on whilst pressing the brake pedal.
Could this be an issue with the CCM all along?
Is there a specific part number for Seat or are they interchangeable from VW/Skoda etc

Its more like a earth problem ! which I said a few posts ago

 

[Upia]

I inspected the earth point in the rear, scuffed up the connections and reattached them. They were all fine beforehand, no corrosion or damage anyway.
I’ve got it booked in Friday so will hopefully find out what the issue is once and for all then.

This was the earth point I got to. There’s another wire there for a rear camera that’s no longer in use from the previous owner, but everything else appeared normal.

 

[RADIOTWO]

I inspected the earth point in the rear, scuffed up the connections and reattached them. They were all fine beforehand, no corrosion or damage anyway.
I’ve got it booked in Friday so will hopefully find out what the issue is once and for all then.

This was the earth point I got to. There’s another wire there for a rear camera that’s no longer in use from the previous owner, but everything else appeared normal.
View attachment 40666

Try running a wire from that point to the earth terminal on the back of the lamp holder, and see if your fault goes