Why did my fuse box melt?
Posted: 29 Nov 2025, 22:11
Coming home earlier in the week I noticed my right hand headlight was out. Side light and main bean still working, just no dipped beam. I had a look the next day and swapped the bulbs to test them, both bulbs were fine. A voltage reading was fine until the bulb was connected when it dropped, which suggested a dodgy connection. The connector for the bulb was a little cracked and the spade connector pretty manky - I was putting in a Brickwerks order for some other things so ordered some new ones as well.
Swapped over the connector today but no improvement. I then checked the other end at the fuse box and found a molten mess. In hindsight I should have had a look there first!


So happened here? Was it a bad fuse which didn't blow when it was supposed to? Bad connection / rust / debris in the fuse box? Anyone had this happen before?
I remembered that the previous week there'd been a smell of burning plastic when I left the house, it didn't seem to come from anywhere specific, there was no smoke and it passed, so I'd put it down as coming from somewhere outside...
Wiring is as factory as far as I know and can see, no relay mods added. One thing I wasn't sure about is that I have 2 wires coming out of the "M" connector on the back of the CE1, one white and one yellow. Bentley shows these as connected to the lighting, but lists them as open, so where do those wires go? They look factory.
Longer term I'll need to replace the CE1, but shorter term I'll need to cut some wires and route around it via a separate fuse. I guess the questions are; should I also do the left hand side, and should I do a relay mod while I'm there?
Swapped over the connector today but no improvement. I then checked the other end at the fuse box and found a molten mess. In hindsight I should have had a look there first!
So happened here? Was it a bad fuse which didn't blow when it was supposed to? Bad connection / rust / debris in the fuse box? Anyone had this happen before?
I remembered that the previous week there'd been a smell of burning plastic when I left the house, it didn't seem to come from anywhere specific, there was no smoke and it passed, so I'd put it down as coming from somewhere outside...
Wiring is as factory as far as I know and can see, no relay mods added. One thing I wasn't sure about is that I have 2 wires coming out of the "M" connector on the back of the CE1, one white and one yellow. Bentley shows these as connected to the lighting, but lists them as open, so where do those wires go? They look factory.
Longer term I'll need to replace the CE1, but shorter term I'll need to cut some wires and route around it via a separate fuse. I guess the questions are; should I also do the left hand side, and should I do a relay mod while I'm there?