Brake lights and horn not working, 2006 S2R1000. details in post

[superkain]

All,

I have run into an issue where my horn and OEM brake light simply ceased operating.

I replaced my handlebar at some point, but neglected to check the lights and horn, as the bike fires right up. I am not sure this is connected to the issue.

Brakes switches are BOTH good, I've tested them at the juncture to the wiring harness. both show continuity when pressed.

All the fuses are good, none have blown.

I have good continuity for all three wires to the OEM brake light; the running light is on, and not the brake light.

I don't get any signal on the red w/ white stripe wire from the main wiring harness going into the tail light subharness when activating either brake lever.

This bike is almost entirely OEM.  Is it possible that there are broken wires within the main wiring harness that are affecting the brake light, and maybe horn?  Is there a likely suspect that I am overlooking?

[superkain]

Turn signals all work.

Hi and low beams work.

No other symptoms of problems with the bike.

[ducpainter]

Monsters have a weak point in the wiring harness where it wraps around the steering head. It's not uncommon to find broken wires in that area.

[stopintime]

I'm not an expert at all, but...

Maybe age has eaten it's way into the harness (contacts and/or wires). That's going to take time. Maybe a new harness.

Horn connectors are lousy quality from the factory. Clean/rinse/sand/tighten? Poor power can also silence a horn.

The large rear lights+turn signals sub harness connector, under the right side under seat cover, is always exposed to the weather. That's where I look first when my rear lights shut off.

[superkain]

So, the simplest solution is probably the right one.

I replaced the 100% perfect appearing 10 amp fuse for brake light and horn, and everything starts working.

[stopintime]

 

[ducpainter]

So, the simplest solution is probably the right one.

I replaced the 100% perfect appearing 10 amp fuse for brake light and horn, and everything starts working.

Appearances can be deceiving. Check the old fuse with a meter just to satisfy my sick sense of humor.

I run a mower at the racetrack that will occasionally shut down for no apparent reason. Last time it happened I walked back down to the shop to get tools, and went back up to diagnose it. Checked everything I could think of. Used a meter to check the fuses. Everything checked out fine. Pulled the starter solenoid fuse and reinstalled. Been fine ever since.