The first step is obviously to get some new 12 volt parts for your bike – mainly bulbs and a battery.
I decided to leave my existing 6 volt horn in place as that should work fine on 12 volts (at least for a while!
) and as it’s a cheap pattern part I’m not too worried if it eventually gets fried.
If you have the original Lucas unit you might want to swap it though to avoid damage.
I guess you could just cut this off, but that would make it more difficult to revert back to 6 volt operation in the future if needed.
After a quick double check of the wiring to make sure it all looks in good order, the new 12 volt battery can then be installed.
With the white wire removed from the ammeter connection, you then need to make sure that it is insulated so that it doesn’t short on the frame etc.
I used some heat-shrink tube to cover the bullet connector at the end of the wire.
Now I’m not sure exactly why 6 volts was chosen, but I’m guessing it’s something to do with the ‘cell’ voltage of a lead acid battery being around 2.1 volts and three cells giving a battery unit of a convenient size.
I didn’t really want to bother going to the hassle of getting another one made if it would only last another few months.
On top of this, I was looking to fit some indicators to the bike in the near future (to make riding feel that little bit safer) and preferably wanted to use LED bulbs to minimise the additional load on my small Lucas dynamo.
In standard 6 volt operation, both the brown and white leads out of the regulator unit are connected to the ammeter.
For 12 volt operation, you just need to remove the white wire so that only the brown one is connected to the ammeter.