No Trailer Brake Lights when Connected to a 2004 Harley Heritage

Updated 06/19/2015 | Published 06/18/2015

Question:

we have the plug and play on the 2004 Harley heritage. we have everything but brake lights. there is a blue wire on the plug and play, where do we connect it for brake lights.will the plug and play we have work?

asked by: Joe

Expert Reply:

Motorcycles and trailers designed to be towed by motorcycles have brake lights that are separate from the turn signals. In the US, regular trailers have combined brake lights and turn signals on the same circuits, one for each side.

If the harness on your Harley is set up with separate brake lights and turn signal circuits but the trailer has combined, then that could be why you are not seeing brake lights. This would also be the case if the connector on the bike had combined circuits and the trailer required separate.

If the trailer has amber turn signals, then it is a separate system. You can use a circuit tester such as # PTW2993 to test the connector on the bike to determine if it is combined or separate.

Once you have identified if the bike and trailer are combined or separate, we can determine a course of action. We do not sell custom fit wiring harnesses for motorcycles so I cannot say what the function is of that blue wire.

expert reply by: Michael H