Tail light works, no brake light

[med.jeeves]

2012 S10, 34,XXX miles, 3rd owner.

My tail light comes on, but my brake light does not. I'm pretty vigilant on checking lights (and other stuff) every time I leave the hosue. Last time they worked I had ridden the bike into work, and got rained on at work, and for the ride home. They brake lights worked when I left the house. It was parked for about 10 days, and last night when I went to go for a ride the brake lights no longer worked.

A previous owner had installed a Dyna Flash rear brake light modulator, and when neither brake switch would activate the brake lights, my guess was the Dyna Flash module had gone bad. Pulled the Dyna Flash out, still no brake lights. All the fuses were good when tested with a test light, but I don't have a volt meter or anything really technical. As far as I'm aware all of the fuses are under the right side cover. Please correct me if I'm wrong.

So ... I'm still at square one with a working tail light, and no brake light. All other lights on the bike work. Is is possible that both switches went bad at the same time? Is there anything else I'm missing?

 

[SeaBass]

I'm going to assume once you pulled the Dyna Flash, you reconnected the wires back to their original state.

It is unlikely that both brake switches went bad at the same time, but is easy to check, disconnect the cable from the front brake switch, and just bridge the connectors with a paperclip, if you brake lights do not turn on, then is not the switch. Check the cables again and you might need to trace the wires to find where it might had gotten snapped.

If it turns on, then is the switch, do the same with the rear brake to make sure is the switches and not wiring on that one either. and replace as needed.

 

[Sierra1]

Are you sure there's not a relay or harness that you missed with the Dyna Flash? It is possible, but unlikely, that your switches went bad. Also, check all the electrical connections. I'd start with the ones that the Dyna Flash was connected to. You might have some corrosion that developed over the years. Dielectric grease is your friend.

 

[gv550]

Blown light bulb? Or does the gen 1 have LED?

 

[bimota]

i think all rear lights are a led unit my gen 1 is

rob

 

[med.jeeves]

Gen 1 is LEDs. The Dyna Flash was (unfortunately) spliced in with vampire clips, and the original Yamaha plug was left "open" and unconnected. The wires have been repaired where needed with heat shrink crimps, and I'm a very big fan of dielectric grease. I'm going to try bridging the switches (thanks for that), but my current fear is that I'll be chasing electrical gremlins for who knows how long.

Keep sending any suggestions my way, and I'll keep trying them.

 

[BadNews]

Parked for 10 days? Plenty of time for a rodent to build a nest under the plastic part that the pillion seat mounts on, lots of room under there and they like to chew the wiring that goes through there. Don’t ask me how I know.

 

[med.jeeves]

Well - bridged the connectors for the front and rear switch to no avail, which means its something worse.

I'm not too worried about rodents (though I certainly feel for you). A big ol' orange tom cat likes to sleep under my car or bike, depending on the time of day.

I'm through working on her tonight - I'll start trying to trace wires tomorrow.

 

[Cycledude]

Bulb

 

[Don in Lodi]

I was going to suggest the brake light is stuck on, not that it won't come on at all. What does your test light tell you?

 

[med.jeeves]

Don in Lodi for the win!! Brake light was stuck on.
It looks like one of the wires that had been spliced into for the Dyna Flash had a break or a short in it. Went back a few inches from the plug towards the battery on the blue wire, and just replaced that entire section. Now have working brake lights, though no more flash. Time to try and find a plug in module.