Which Circuit on 6-Way and 7-Way Controls Reverse Light Circuit

Question:

Hello, My boat trailer has a 5-flat wiring whip. I have a pre made connector to 7 pin round when I tow with my truck. My motorhome currently has a 6 pin round that Id like to change to a 7 pin round for ease of use with all my trailer. I believe the 5th wire overrides the surge brakes on the boat trailer when in reverse. Is this correct? How does this wire to reverse if so and what parts would I need? Thank You,

asked by: Louis B

Helpful Expert Reply:

The reverse light circuit of trailer wiring is what overrides the reverse lock out solenoid of a surge actuator to allow the trailer to back it up without brakes locking up. On a 6-way this circuit should be the center pin. This is also true on 7-ways like the part # PK11700 you referenced.

helpful expert reply by: Jameson C