Brake light goes off when brakes applied?

[mwc]

Hey guys, I just put a new front master cylinder that has a brake light switch on the RMX, as it came with no brake lights. The bike has a Tusk lighting kit with wires for brake light and running light. Before wiring the switch the taillight worked, but I'm not sure if it was running the brake light LEDs also or just the running light.

After hooking up the switch, the light goes out when the lever is pulled. I opened the switch and with the brake lever in its resting position the switch is open, and when the lever is pulled the circuit is completed and the light should come on.

I don't think there are any wires crossed but it could be a possibility, maybe a bad ground? Ran out of time last night, gonna mess with it some more tonight after work.

 

[zoomsplat]

So, to be clear, the brake light is always on, then you pull the brakes and the light gets dimmer (goes to "tail light mode") or does it go off completely?

It sounds like the tail light wire is run to the brake light switch, and the brake light wire is run to the tail light circuit. Does it ground through the brake light switch, or run power through the switch then to the bulb? Do you have a schematic for the system?

 

[bobl]

I had that problem, and it was a bad ground. Easy to check, just identify the ground wire for your socket, and use a jumper from your battery ground to the bulb housing, or to the ground wire connection on the socket. On mine, the taillight was grounding through the brake light filament, but both went out when activating the brake light. It was just a dirty connection on the plug.

 

[mwc]

Got it worked out. Talked to Rocky Mountain ATV today, apparently Tusk is their brand. Was able to have them send a wiring diagram and the issue was I had a different taillight than the one that came with the kit. Same 3 wires, yellow black red. Turns out yellow is ground on the Tusk kit, but black is ground on the taillight I have. Swapped those around and it works perfect.

I'm pretty slow with electrical, figured just match up the colors since they both had the same colors. Guess not always.

Thanks for the help guys