Just tested the wiring on my 27 T. It has a new taillight from langs. It does not turn on when switched to dim or on.
I am wondering if it is supposed to be grounded for it to work? Its on a speedster with a wooden subframe, and is screwed into wood. Do the screws normally ground to the fenders or something or it does not need a ground and my bulb is toast?
Yes, the tail light requires a good ground to work correctly. The easiest way to check for that is to flip up the back floorboards, hook a test lead to the POS post of the battery and touch the bolt in the back of the light assy. It should light up. If not connect the test lead to a good ground and check the light lead itself for power.
Connected a ground from a mounting screw to the battery ground. All is good now, it works nice and bright now.