What are the Wire Function on the Adapter 4 Pole to 7 Pole Vehicle End Trailer Connector 30717

Question:

I am connecting this from an old Lexus Rez x300 with the four prong flat outlet in order to use it with my boat trailer. My main concern is at ringing it correctly so I dont lock up the brakes in reverse .

asked by: Deborah M

Expert Reply:

On a 4 to 7-Way adapter like # 30717 you will have to make sure the yellow wire is connected to a reverse light circuit. You can tap into a reverse light circuit at the back of a reverse light. On a trailer with hydraulic brakes and an electric reverse lockout, it is the reverse light circuit on the vehicle that operates the solenoid to allow you to back the trailer up without the brakes engaging.

The white wire on the harness gets grounded to the vehicle frame. Black is for 12 volt power if needed and will attach to the vehicle battery via a 40 amp circuit breaker # PK54540. And the blue wire would connect to the blue wire on a trailer brake controller but if you have hydraulic brakes with feature will not be needed.

expert reply by: Michael H