CB125 Wiring
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Wiring Issues with my CB125
Upon checking over my CB125 after purchasing it, I found some electrical issues that needed attention. Of course, after sitting unused for 10 years the bike needed a new battery. Once the battery was fitted I realised that there was no horn fitted.  I was able to purchase a 6-volt horn from local dealer Cycle Care. I then wired it up (see photo at right) and connected it to the harness.
I also discovered that the rear light did not work. As the stop light was working, I assumed that it was simply a defective bulb but the problem persisted after new bulbs were bought and fitted.  I discovered that the rear light worked when the ignition switch was turned to the 'park' position but not when turned to the 'on' position. I decided to inspect the various connections, hoping that I could find a loose connection.
Wiring underneath the seat and inside the headlight shell
Unable to find any loose connections, I suspected that the problem may lay with the ignition switch itself. A new replacement ignition switch was ordered and, once fitted, fixed the problem with the rear light.