Adding Trailer Wiring to a Motorcycle to Tow a Trailer

Question:

My bike has round 5 pin b= taillights w is ground y isL turn and g is right turn and red is break my trailer only has 4 bought a converter and only get power past converter to to brown wire and ground please help

asked by: Rodney R

Expert Reply:

Motorcycles have separate brake lights and turn signals. Most trailers, unless designed for use with a motorcycle, have combined turn signals and brake lights. You will need to convert the separate signals on the bike to match what the trailer requires.

To do this you will need a converter like # 119178. On this harness you will connect the white to ground, green to the left turn signal, yellow to the right turn signal, and red to the brake lights. Brown is the running lights. If it is combined with the brake lights then you will attach the brown wire to the brake light wire and ground the red wire with the white wire.

If this is the same set up you already have and the trailer was designed for a motorcycle then it is possible that the trailer does use a separate system with brake lights and turn signals on separate circuits. If this is the case then you can tap into each circuit separately using a 5-Way harness such as # HM47900. Normally the 5th pin is used for a reverse electric lockout but for this application you can use it as the brake light signal. This may require rewiring the trailer side connector to match.

If you can give me more information about the trailer connector type on the trailer and if the trailer has turn signals separate from the brake lights I can make a more definitive recommendation.

expert reply by: Michael H