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Motorcycle Repair/Honda C100 wiring


I am restoring a 1964 Honda C100.  The wiring was all disconnected.  It has a brake switch but the wiring diagram for the C100 doesn't show a brake switch. Also, the rectifier has 3 wires--a white and two reds.  The wiring diagram only shows one red and one white wire.  What do the wires from the rectifier and the brake switch connect to, please?  

Thank you very much.

Hi Al,

The rectifier on these is just two wires as the red is just a double connection.
The red is the power for everything and connects to the battery positive
as well as signal flasher, horn and neutral light etc.

The white wire goes to the ignition switch which then connects it to the stator
coils yellow AC current.

So the stator or flywheel coil yellow sends juice to the ignition switch which then
redirects this power to the rectifier and then on to the red wires for DC battery
charge and to other battery powered devices as I mentioned above.

This yellow wire power is also redirected by the switch to power the lights
on a brown wire.

It can be a bit confusing so if you need to rewire it feel free to ask me followup

The brake switch just needs some power on one side and then the other side goes to the
brake light bulb filament in the tailight if so equipped.
You can just connect to power on the ignition switch or battery red.

There is the possibility you have some modified wiring or switches
unless it is all original.


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Wayne S.


Licensed Motorcycle Mechanic, Knowledge of motorcycles from 1960 up, Japanese, British and most other brand motorcycle repairs.


Worked for Yamaha, Honda, Suzuki, Kawasaki British: Triumph, Norton, BSA Other: Most Scooters and Mo-Peds

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