Front brake, brake light doesn't work.

[pichulec]

Hello, I have realised today that my front brake light doesn't work. But, the problem is that rear brake light does work. I have checked the switch, switch is OK. I tried to bridge the cables together, still no brake light. When I press rear brake pedal then brake light coming up. I suspect cable from the front is torn or disconnected somwhere. Do you blokes have any idea where under the seat I can check continuity of that front brake switch cable?? Also how this operate? is it ground being split when the switch is pressed??

[purplebikeunicorn]

Not a lot in that circuit.

There is a connector just before the brake light switch (and all the other controls on the rhs), check the pins and wires are OK. The O/G and W/B wires (B/R and B/Bl switch side of the connector) are the brake light switch, and shorting them together should show a brake light.

I would also double check the switch can actually carry power, it might test OK for continuity, but can it carry 21W? (just under 2A).

https://www.v-strom.co.uk/downloads/V-Strom%20Workshop%20K6.pdf last page, top of the diagram by the ignition switch

[pichulec]

O/G and W/B what colors they stand for? Where I can find them in fuse box?

[purplebikeunicorn]

They won't be in the fuse box. The signal fuse is fine as your rear brake light works.

If you follow the wires back from the brake light switch, you will come to a multi-way connector. Split that connector and check the pins/wires.

[pichulec]

Well, the problem is that connector is behind radiator, not accessible without stripping the bike... Where I could piggy back to rear brake switch?

[pichulec]

I chave checked the front switch wires and one of them have power, the other is shorting to ground. I assume it not supposed to, right?
Where I could piggy back to rear brake switch?

[Gert]

Did you pull / disconnect the stop light bulbs from the circuit, when you did the earth test?  The earth that you are reading is possibly a resistance earth, as the bulb common is to earth.

If it too much trouble to remove the stop light bulbs, make use of a test bulb. One leg of the test bulb on battery pos (+) and the other to the neg lead of the stop light, where you measures an earth. You should be able to see if the both the test bulb and stop light bulb burns however faintly.

[pichulec]

They are LED bulbs, no I haven't disconnected them during test.

[UK_Vstrom650]

It sounds like you may need to inspect the connector behind the radiator - if there's potentially corrosion on one wire, you might be better off checking the others too.
I think to get to the rear switch to piggy back, you're going to have to remove the panels/tank anyway?

[pichulec]

Sorted the easiest possible way. Run the new wire from one side of the switch to brake light + I did piggy back at the rear loom next to the subframe. White and black wire. I am not fancy checking the connector behind radiator as to get to it would have to strip half of the bike. I did not have to remove any panels to fix. Thanks for help.

[purplebikeunicorn]

I would definitely have this as a job to do when the weather is shoddy and you have time. As uk says, if one pin/wire in that connector is corroded and broken, then others may be too.

If it was a true ground on the one leg of the switch, then it should in theory blow the signal fuse when you pull the lever. I expect you're just measuring a path to ground through the bulb.

[pichulec]

Connector has been cleaned and waterproofed recently when the valve clearances were done. I assume it should be OK. Probably broken wire somwhere.