W/NG - broken MT110

 Checking over the W/NG yesterday whilst babysitting the two youngest revealed a bike that started, whose lights worked with a new battery but no brake light. A bit of nosing around soon found the problem - all the wires to the Lucas MT110 rear lamp were torn out of the fitting somehow. Since it's been sitting in Thomas' garage surrounded by bicycles, tools, other motorcycles, lawn mowers and the accoutrements of three small boys it's hardly surprising that it's suffered some damage. 

The problem is that I have very little time to repair the lamp before I need to ride it back tomorrow. I bought the lamp back to the workshop to give it a dose of looking at.

The first job was to sort out a way of replicating the contacts in the lamp base. I discovered that these boot lace ferrules I had in the terminals box have a slightly belled end and you can thread a new wire through, spread the strands out and add a blob of solder.

That's the first problem fixed.

Next is to sort out the earth connection. I thought that the original earth wire was soldered to the outside of the lamp holder - turns out I was wrong about that but what I planned to do was put a washer type fitting inside the lamp base and solder a wire to that, like this:

I eventually found that actually the original wire was soldered to a brass washer which was still there, and which I could have used. Hey ho.

The next bit, and apologies for the terrible picture, was to add some heat shrink to the rear lamp and brake lamp terminals to add a bit of extra strength. This is actually a bit long and inhibits the deflection of the connectors as they go into the bulb holder. 

Reassembling the lamp left me with something that didn't work at all. I pulled it all the part again and realised that the inside of the bulb holder was corroded and I wasn't getting an earth connection. The Dremel fixed that along with a bit of sandpaper.

So that left it all working again and hopefully I can bring the bike back tomorrow. I might pull this lamp apart again and use the original brass washer, since the spring is not in very good shape and is rather weak.