E46 M3 rear fog light issue - and fix
Discussion
Just thought I'd share my experience on this one, in case one of you has got a broken fog light which you can't seem to fix.
I've got my MOT on Thursday and the rear fog light decided to pack up today, and wasn't very straightforward to diagnose and fix...
1. I swapped the bulb with the reversing bulb, and found the bulb was fine.
2. I tested numerous fuses with a multimeter (essentially anything remotely associated with lights - there's no single one marked 'rear fog light'). All fine.
3. I checked the continuity of the wiring from car to bulb and back again (ground and live cables). Fine.
4. Scratched my head a bit, and decided one of the above can't be right.
5. Did all of the above again, but this time 3 was no longer the case. Pulled back the rubber sheath around the wires which go from car to boot lid. Bingo - broken wire. I guess it was intermittently carrying current due to me opening/closing the boot.
6. Replaced the wire. Working again.
Hopefully it flies through the MOT!
I've got my MOT on Thursday and the rear fog light decided to pack up today, and wasn't very straightforward to diagnose and fix...
1. I swapped the bulb with the reversing bulb, and found the bulb was fine.
2. I tested numerous fuses with a multimeter (essentially anything remotely associated with lights - there's no single one marked 'rear fog light'). All fine.
3. I checked the continuity of the wiring from car to bulb and back again (ground and live cables). Fine.
4. Scratched my head a bit, and decided one of the above can't be right.
5. Did all of the above again, but this time 3 was no longer the case. Pulled back the rubber sheath around the wires which go from car to boot lid. Bingo - broken wire. I guess it was intermittently carrying current due to me opening/closing the boot.
6. Replaced the wire. Working again.
Hopefully it flies through the MOT!
Gassing Station | M Power | Top of Page | What's New | My Stuff