So your tail light doesnâ€™t work and youâ€™ve already checked the bulb; itâ€™s O.K. Now what?
Plan on removing the seat and doing some detective work. The wiring that runs under the seat to your taillight lives a tortured existence down under your butt, taking abuse from the seat action and movement, as well as vibrational friction in the tight quarters. Many times you will find an open in the wiring, or a short to the tunnel that is thwarting the efforts of the lighting system. Often there is a connector under the seat, so you can unplug the tail light and do some continuity checks with an ohmmeter (multi-meter). On the supply side you can easily perform a voltage check on the open connector to troubleshoot the problem. Remember, you need both a supply voltage and a ground return path for the circuit to be complete and for the bulb to illuminate properly.