Hi all

I'm the new owner of an 02 plate Fabia 2.0l. The previous owner (friend of a friend) had it MOT'd just before I bought it and explained that it had failed the MOT due to an unlit brake light. The garage wasn't able to find the source of the problem but hard wired the bulb from the other side to get it through the test. I bought it knowing this, but I'm now trying to cure the problem to avoid the bleeping sound associated with the warning signal on the dash.

The problem appears to be intermittent, and seemingly occurs more when it's a cold morning - sometimes I can start a journey and have no warning light.

Any tips on where to start with diagnosing it? Does the brake light switch have separate feeds for each light, and therefore could it be a brake light switch failure? If so, I'll try replacing this first.

Other thought was that the ECU was replaced in the not too distant past - could it be linked to that at all (dodgy connection etc)?

thanks - greg

firstly i would re connect the bulb then start tracing the wire back .... you can then test any connections / joins with a multimeter it may just be a dodgy plug ?

If the brake lights work, or the other one and the high level one, then it's unlikely to be the switch IMO. If I were you, I'd get into the cluster and check for corrosion and clean up the bulb connection and look for any loose/ corroded cable.

Thanks for the replies, will take a good look at all the connections this weekend. Must be a connection somewhere for it to only occur when it's cold.

Took the cluster out today and established it's actually the rear nearside tail light that is hard wired to the other side, not the brake light. If i remove the wiring mod, there is no voltage across the live wire for the nearside. I tried to follow the wiring loom and got as far as it disappearing under the rear seats?

Can anyone help with a diagram of where the next connection is? Is there a connection to the fuse box?

both nsr and osr rear lights should join somewhere around there .... might be worth taking the rear seats out of the car ( 2 min job) and boot carpet (2 min job) and trying to follow the wires to where they join the main loom

Just been reading up on the wiring in the Haynes. Suggests LH tail joins LH front side light and are both fused by F34. F34 is ok (LH front side goes off if i remove F34 fuse).

So looks I need to find the connection somewhere between fuse box and the tail light where it is joined with the front side.... any ideas??

Bump. Do I need to get the whole fusebox assembly out?