My reversing lights don't work, there's no current at the bulb.  Does anyone know if they are on a separate fuse?  I looked in the owners manual, which suggests fuse no. 4, but I substituted a new fuse without success.  I suspect it may be a faulty switch on the gearbox.  I have a diesel Mk2 Octavia on an 06 plate.

21 minutes ago, cheadleskoda2 said:

My reversing lights don't work, there's no current at the bulb.  Does anyone know if they are on a separate fuse?  I looked in the owners manual, which suggests fuse no. 4, but I substituted a new fuse without success.  I suspect it may be a faulty switch on the gearbox.  I have a diesel Mk2 Octavia on an 06 plate.

One car I had, the reversing lights flashed when you went in or out of reverse, and could be held on by holding the stick to the outside of the gate. Issue was a bent switch bracket, which we just lived with, and testing yours should be free...

Edited 24 August, 20232 yr by Paws4Thot

If you have working rear parking sensors it's not the gearbox switch.

 

Check for corroded bulb contacts.

Thanks.  No parking sensors.  Think I'll check the switch.

Switch or wiring break at switch connector.

Still wrestling with this.  There's no current at the switch connector.  I checked both pins with the ignition on and the car in reverse.  Maybe there's a break in the cable somewhere?  I noticed some sort of small junction box before the switch connector but I'm reluctant to open this as I'm not sure what it's for.

Photo of junction box?

Bloody hell, I've just replaced the airbox.  I'm now an expert at this!  It's a black plastic T type box, maybe 2" long and it looks like you can unclip the lid.

I wonder if someone has repaired before, using a new connector with wires pre-fitted, and grafted it into the original loom at this box? In which case check within. I doubt it's part of the original car.

 

Thanks.  It looks original fit.  I guess the supply could be shared with something else.  A wiring diagram might help, do you know where I can find one?

The only junction shown in the wiring it the one labelled B279, which the key describes as "Positive connection -3- (15a), in interior wiring harness" [my bolding].

Grey box at top of diagram is the onboard supply control module inside cabin.

So both wires should run continuously into cabin, I believe. What colour are yours where they emerge from switch?

Diagram suggest they should be black/yellow from fusebox and blue/black to control unit.

 

 

Yes, I think those are the colours.  I'll have to remove the airbox again to make sure (maybe tomorrow).  Does this diagram show which fuse they are on?

Cabin fuse 4 feeds junction B279, as expected. it also feeds some other things, so I think it would be apparent if it had blown.

Thanks.  I've parked this for now because it's not an MOT item on this car.  I'll try the junction box when I have time.