Brake light issue troubleshooting

Hellooo! Just got my new regulator so trying to get all my lights up and working.

I have running indicators, headlight, tail light even but my brake light will not light up!?


The globe is fine. I first tested at the plug under the seat and I do not get current on the brake light pin by pulling either brake lever.


I then tried bypassing the front switch altogether by running a wire across the terminal it plugs into behind the headlight but still no dice!? Surely that should have lit it up?


Any ideas? A ripped/cut wire along the way seems unlikely but its about all I can think of.


Seeing as neither lever works could the problem be located where they share the same wires?


Any and all help much appreciated, thanks!

What bike?

Check the actual switches. Put a multimeter across both wires to brake pressure switch and push brake lever to check continuity. Do same for front brake switch.

Thanks for the reply!

Sorry, 04 WR450, they come road legal from factory here in aus I think it's different elsewhere?

I figured if the switch was the problem bypassing it at its plug would have fixed it? I will check anyway.

Gonna be out there all day with a multimeter.

No continuity with lever pulled. Bypassing the switch by running a wire between the plug terminals does not create current. There is about half a volt between the two plug terminals. This means it must be a bad connection somewhere between the battery and that plug, right?

Thanks again.

The brake light circuit is a pretty simple one. Just gota get it sorted in your head so you can test it correctly.




Diagram shows a common relay, but yours might just be a common joint. "Basically" same for all bikes.


Work you way through, you'll get it eventually



Thanks for the diagram. Haha yep I thought I might be testing wrong.

I'm thinking about just rewiring the front plug to the battery + on one side and brake light + on the other. That will 100% fix any problems unless it is a grounding issue.

Fixed! Pulled some un-factory-looking elec tape off and found that some turkey had cut the brake light+ wire at the rear plug!? :confused:   Reconnected and its all working fine now on both levers. Thanks for the help, that diagram is actually different to what I had assumed it would be so im glad you posted it!


EDIT: and please excuse my shameless double posting habits

Edited by Wounded Lobster


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