Topic: Right side control switch issue. 72 CB750

[Malcolm]

Hi there,

I just installed a new right side control switch on my 72 CB750, and I'm hoping you can offer me a bit of advice.

I am running into a couple issues:

The brake light is always on

The bike won't start unless the headlight is switched on

Turning the headlight to "off" kills the engine.

When I installed it I had to get a hole drilled through the bottom of the case to run the wiring through.

**UPDATE
I have managed to get every problem sorted except one:

The brake light won't work at all until I turn the headlight on. When the headlight is on the brake light stays lit regardless of any brake lever being pressed.

[Keith]

Was it an identical switch? Same wiring colors? Aftermarket? Sounds like you have the wires mixed up.

[Malcolm]

It's been resolved thanks for your interest though!

[PeWe]

Exactly which wires that were wrong connected will most likely help others with same future problem.

 My recommendation is to mark each wires after check of the function with a buzzer and circuit diagram beside before maount it on the bike. I did that with both my new control switches. Only issue I had was a missing jumper between brown and black.

[Nic]

Colour blind?

[Malcolm]

I would love to explain what I had wrong, but my friend ended up trying a bunch of combinations in the headlight and sorted it out.

[Keith]

It's easy to take photos before taking apart as a reference. Wiring diagrams are an essential tool.

[Malcolm]

It's easy to take photos before taking apart as a reference. Wiring diagrams are an essential tool.

As I removed each wire from the old control I swapped it out with the new ones. They all ended up where the old ones were, that's why I was so confused as to why it wasn't working.