Converting 4-Pole Flat Wiring to 7-Way for Use with Boat Trailer Having Electric Brakes

Question:

My vehicle has a 4 way plug, but not a 7 way. I recently acquired a boat and trailer has electric brakes. I need to either convert to a 5 way or 7 way and would prefer not to splice reverse wires. Would prefer the 7 way because on occasion I do pull a friends boat and could easily convert back to 4 way. Is there a plugin part available which solves my problem?

asked by: Dan M

Expert Reply:

We do offer wiring adapters such as # 20036, # 47515 and # C57187 that allow converting 4-pole flat type wiring to a 5-pole flat format that includes an additional circuit for a trailer surge coupler's reverse lockout feature. An example of such a coupler lockout solenoid is part # T4748800 from Titan. This has a 12V powered solenoid that blocks the flow of hydraulic fluid to the trailer's brakes, letting you back up the trailer without the brakes engaging. But all of these do require you to splice one wire to gain access to the reverse light signal.

Boat trailers that use electric drum brakes do not require a reverse lockout circuit but they do of course require a brake circuit to deliver power to the electric drum brakes. If the trailer also has a battery (to power an electric boat winch) you'll want the 7-way set-up since this format can provide both brake signals and also 12V auxiliary power to maintain the trailer's battery.

Since you already have a 4-pole harness you'll need just our kit # ETBC7 to convert this to the 7-way format. This same kit also allows installation of a trailer brake controller, such as the Prodigy P2 # 90885, which is an excellent choice for its mix of useful features, its value and for its proven reliability. An installation video showing the entire process of installing the # ETBC7 kit and the Prodigy P2 # 90885 controller, as well as a helpful article, are linked for you.