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Motodynamic LED taillight brake light not working

832 Views 0 Replies 1 Participant Last post by  suruppak
Hi All,

I have a 1999 Monster 900 that I recently bought, and it has a Motodynamic LED integrated taillight, with turn signals, brake light, tail light, and license plate light all contained in a sealed unit. The regulator failed and it boiled the battery over and blew all the fuses. I cleaned up the mess and replaced all the fuses. Now, everything works, except the brake light.

1) All fuses are good
2) All the brake switches are good. The brake light wire is Gray with a Red stripe, and when I attach a light to it and press the brake pedal, the light lights up. See Pic.
3) In this integrated unit, I notice that when the tail light is on, only half of the LED bulbs light up (see picture). This leads me to assume that when the brake light is activated, probably the other half of the LEDS are supposed to light up as well, lighting all LED bulbs for maximum brightness.
4) When I plug the Gray/Red wire from the bike into the White (brake light) wire from the integrated unit and press the brake pedal, I notice nothing happens, no additional LED bulbs light up.
5) So, I unplugged the Yellow wire (bike taillight) from the Red wire (Integrated Unit taillight) so all the LEDs are now dark. Then I plugged the Gray/Red (bike brake light) into the Red wire (Integrated Until taillight) and hit the brake pedal, now I have 50% of the LEDs lit up, the same 50% as the taillight as you would expect; just an additional proof my brake lights are sending power to the LED unit.
6) So then I plugged the Gray/Red (bike brake light) in the White wire (IU brake) with no taillight wires hooked up and hit the brakes. Now once again 50% of the LEDs are lit up, the same 50% for the taillight. I did this again by putting the bikes Yellow wire into the IU white wire (bike taillight to IU brake light) and the same 50% of the bulbs lit up.

So, all of this fiddling around proves to me that the Motodynamic unit is getting power from the taillight wires and brake light wires as it should. However, the same 50% of the bulbs (and I mean the same exact bulbs stay lit and stay dark) regardless if the power is coming from the brake light or the tail light.

Does this mean the Motodynamic unit is bad? Is there something else I can consider? Is there a way to open this unit and repair it?

Thanks and sorry for the long post.