A relay-isolation harness is a good investment if you're planning to pull a trailer. This setup allows you to drive a set of trailer lights (standard bulbs or LEDs) without affecting or loading the bike's signal circuits.
In the event that a short develops in the trailer wiring (typically in the plug area), an inline fuse in the relay package protects both the bike and trailer. Your bike's lights will remain unaffected and continue to work. This video explains how an isolating circuit works:
Check out our installation video:
Which kit fits MY Harley?
This US-made kit is designed to plug-and-play with most Harley touring bikes from the mid-90s to present. The adaptor kit you want depends on the model and year of your bike. (See pictures at bottom of this page. Click on them to enlarge.)
Square "AAMP" connector: 9 times out of 10, this is what you will want. This fits almost all Harley FL bikes from 1997 to 2013 (see exceptions below). The connector is located under the seat. This includes models from the Electra Glide family as well as Softails (Heritage, Fat Boy, etc.)
Six-pin Molex connector: This connector was introduced on the 2010 Road Glide Custom (FLHRX) and the 2010 Street Glide. It is located under the left side cover.
Eight-pin Molex connector: The eight pin Molex is used in the 2009-13 FLTRSE and the 2010-13 FLHXSE. It is located under the seat.
Older models: If your Harley doesn't fit any of the above categories, you can use the Universal Fit version of our kit.
Do I want a Four or Five wire kit?
If you are pulling a trailer with a flat-four plug, or your trailer has just one set of shared brake lights/turn signals, you want the four-wire kit. This contains a converter that will make your bike's signal and brake lights compatible with the trailer.
If your trailer has brake lights that operate separately from the turn signals, you want the five wire kit.
Due to the variety of plugs used by different manufacturers, bike-side plugs are sold separately. If you are buying a new trailer, your bike-side plug is usually included. If not, you'll find them here.
Live outside the US?
We ship this kit anywhere. Contact us for a shipping price to your country.