Hi All,

A little while ago I retro-fitted cruise control to my 05 Fabia vRS which in the end involved removing the dash (long story!). Anyway, when piecing the car back together I had a minor mis-communication with my other half and connected the battery while the ignition was on, blowing a couple of fuses.

Anyway, changing a couple of fuses and bulbs had the car back in working order but a few days later I noticed the high level brake light wasn't working. I assumed the light itself had been fried but I have since taken it out and tested it and it works fine. So I traced the wiring back from the light into the boot and I'm still getting no voltage on it here.

I'm assuming I've blown something somewhere between the brake switch and the back of the car but have no idea where it could be, or perhaps I dislodged something when removing/replacing the dash? The wiring diagram in the Haynes manual isn't much help, all I know is the wire from the brake switch is black and red, but somewhere it must split into 3 for each of the brake lights, and if the other two are working how can only one not?

Any help or advise would be much appreciated!

What's in position 13/14 on the relay plate?

Did you have the relay plate unbolted when the fuses blew?

If you have a bulb failure module in these positions, then you may have fried it. This module has separate outputs for the three brake lights, so you will find three black/red wires going to the three bulbs.

What's in position 13/14 on the relay plate?

Did you have the relay plate unbolted when the fuses blew?

If you have a bulb failure module in these positions, then you may have fried it. This module has separate outputs for the three brake lights, so you will find three black/red wires going to the three bulbs.

Thanks for your reply.

I'll check tonight but the dash is reporting a fault with a bulb so I assume that means I've got the bulb failure module? Is it possible to be fried and still power the main brake lights but not the high level one?

Do the normal lower O/S and N/S brake lights illuminate if footbrake applied??

Do the normal lower O/S and N/S brake lights illuminate if footbrake applied??

Yep, no problem there are all. In fact just to pass the MOT I've wired the high level light into one of the black/red wires leading to the lower brake lights but that obviously hasn't got rid of the light on the dashboard reminding me something isn't right when I brake for the first time after turning on the ignition.

Thanks for your reply.

I'll check tonight but the dash is reporting a fault with a bulb so I assume that means I've got the bulb failure module? Is it possible to be fried and still power the main brake lights but not the high level one?

Yes.

The dash is reporting the fault on the high level brake light.

A few things to check...

Make sure the module is fully in the socket.

Make sure you didn't pull a wire from the back of the socket.

Check the continuity from the high level brake light to the module.

Yep, no problem there are all. In fact just to pass the MOT I've wired the high level light into one of the black/red wires leading to the lower brake lights but that obviously hasn't got rid of the light on the dashboard reminding me something isn't right when I brake for the first time after turning on the ignition.

This what I was gonna say, it has offending brake light working, but as you state, it hasn't stopped the dash light from illuminating.

I assume you have checked fuses, (not that I think for a moment you haven't).

Probably only answer is to get it along to auto electrician to find the fault.

This what I was gonna say, it has offending brake light working, but as you state, it hasn't stopped the dash light from illuminating.

I assume you have checked fuses, (not that I think for a moment you haven't).

Probably only answer is to get it along to auto electrician to find the fault.

Thanks so much guys, I haven't had chance to check the relay yet plus I only want to check it when the shops are open for me to buy a replacement if it's needed but I'm fairly confident it must be that. If 2 lights work and the third doesn't surely the fault can only be with where they split, being the relay? Is it likely to be a standard relay I could pick up in Maplin etc or will it need to be ordered in by my local Skoda dealer?

And yeah I did check the fuse, in fact I checked all of them to be sure!

Thanks so much guys, I haven't had chance to check the relay yet plus I only want to check it when the shops are open for me to buy a replacement if it's needed but I'm fairly confident it must be that. If 2 lights work and the third doesn't surely the fault can only be with where they split, being the relay? Is it likely to be a standard relay I could pick up in Maplin etc or will it need to be ordered in by my local Skoda dealer?

And yeah I did check the fuse, in fact I checked all of them to be sure!

Although, it's on the relay plate, it is actually an electronic module. You will need to order it from the dealer.

The module has an input from the brake switch and three outputs to the brake lights. The outputs have to be separate to detect bulb failure.

Although, it's on the relay plate, it is actually an electronic module. You will need to order it from the dealer.

The module has an input from the brake switch and three outputs to the brake lights. The outputs have to be separate to detect bulb failure.

I see. I might call the dealer tomorrow, if they're not expensive I might buy one in anyway and just replace it and see if it fixes the problem, that way I won't have to piece everything back together while I wait for it to be delivered.

If you want to do a continuity test, then it is pin 16 on the module/socket goes to the high level brake light.

If you want to do a continuity test, then it is pin 16 on the module/socket goes to the high level brake light.

Brilliant, cheers.