Boat Trailer With 5-Flat plug on 2019 Toyota Highlander with 4-Flat

Updated 03/24/2021 | Published 03/22/2021

Question:

2019 highlander hybrid with an installed 4 wire flat. my boat trailer has a 5 wire flat connector. will lights work, accept for backup lights, brake if I connect the 2?

asked by: Lewis T

Expert Reply:

The 5th wire on your boat trailer is most likely tied into a reverse lockout. What this does when you are backing up it doesn't allow the brakes to engage on the trailer. So without it the surge brakes on your trailer will activate when you're trying to back up your trailer. When you try to reverse the surge brake will think you are stopping causing them to activate. If your surge brake has a manual lockout or override then you won't have a problem. If the electric lockout is the only option you will have issues especially if backing up hills.

If you do need the electric lockout we have the Tow Ready 4 Pole to 5 Pole Trailer Wiring Adapter # 20036. This will allow you to tap into your reverse lights to give you the 5-way working plug.

expert reply by: Bud M