The high level brake light on my 2017 Fabia Estate stopped working.  A warning light signalled "check third braking light".   Thinking that led lights don't normally fail I assumed it would be a power supply issue. From the fuse table in the handbook (page164) I  identified No 1 fuse for parking lights and high level brake light. As the parking lights are operating correctly No.1 fuse must be sound.

I removed the default brake light and confirmed no power to the light. The light proved correct with an alternative power supply.

So my dilemma is, where has the power supply failed?

The wires visible, having removed the light, are in good condition as is the wiring loom as a whole.

Any ideas greatly received.

You need to be in the mk3 Fabia forum with a 2017 car, so I'll report it for a kind mod to move.  Fuse tables have been known to be over-generic in owners manuals so I'd be inclined to check all/others, but only remove/check/refit one at a time, after taking a clear photo of all in original positions.

 

Wiring at the point of entry into the tailgate would be a top candidate for breakage if all fuses are OK, but surely a 5 year-old car is too new to have suffered this??  That's assuming that the high level brake light is mounted on the tailgate, not the main body.

Thanks for your reply and advise.  I will take appropriate action . In hindsight No 1 fuse is rated 40 which does sound a little high for parking and one brake light.

The light is fitted in the tailgate and at point of entry the loom is well bound with no signs of chaffing or damage.

Apologies for being in the wrong place.

With regard to fuses, the other way in which the owners manual can mislead is by having a single diagram that is supposed to assist owners of both LHD and RHD vehicles, where there is often an actual mirroring or rotation of the fuse panel between the two variants.

Well Pete, it looks like a trip to an Auto Electrical Repair unit. I have checked all the fuses in both the one inside the car and the one in the engine bay. All the fuses checked OK using an Avo..

I don't understand why the high level brake light is on a different circuit to the rear brake lights which  incidentally are working fine.

i have considered breaking into the nearside brake light and running a new cable.  Having just written that I have had a thought, the two wires that connect to the light, is one power and one earth? if so then power could be good and earth is at fault.  I wonder!!

 

 

Yep, having a 12V feed is no use if the return path to 0V is broken.

I don't have circuits for mk3 Fabia, but usually the high-level brake light is simply in parallel with the other two electrically.

Thanks for your time and knowledge. I'll try a different tack with earth  and then possibly the alternate route.

 I'll report any progress.

Thanks again.

Hi Hobson

Did you ever locate the problem with your brake light? I’m having the exact Same problem, and I could use some help.

Hi DKBoy,

Unfortunately everything I tried failed to reveal the answer. Eventually I decided to try a local auto-electrics  garage who located the fault to a break of the   wire conductor in a cable showing no signs of ware to the insulation . Not sure of the actual position of the break but they successfully replaced the damaged length of cable.

I found it very difficult to locate the path of the cable from light to a power sauce connection from where I could start continuity tests hence the trip to the garage.

I did manage to remove the high level light  and test it on the bench : it was OK as I thought it would be.

Sorry I can't be of more assistance.

I'm think/guess, that if you remove the high level brake light assembly and prove that it looks okay and then test it to prove it is still working, then the cable break is as said earlier, probably at a point where the cable gets flexed/bent every time the hatch is opened - and that means somewhere at/on or close to the length of cabling that is located within the rubber protective boot that the cabling passes through between the car body and the hatch.

 

If you are very lucky, you will find it by manipulating the protective boot - ie squeezing it with your fingers, and that will reveal an anomaly - if not then it should be close to that area just within the hatch or just within the car body.

 

While the high level brake light assembly is out of the car, check to make sure which side, ie 12V or 0V is missing by having someone press the brake pedal while the ignition is on - noting that the brake lights will also be on at this time.

 

If you have not got a DVM then you will have problems moving forward in this task.

how did you remove the brake light I'm trying tom remove mine to clean the washer nozzle cant see how to remove the high level light unit

On 24/05/2025 at 20:49, MikePH said:

how did you remove the brake light I'm trying tom remove mine to clean the washer nozzle cant see how to remove the high level light unit

Hopefully you've got an answer but I came here with the same question. In case anyone else is looking, I have just removed my wife's by carefully prising off from the outside using a trim tool (but I'm sure any strong / flat enough plastic tool would do the job). The light seems to be held in place by four metal clips which run along the bottom. When done, just pop it back into place.