Activating 12 Volt Accessory Circuit of 2017 Ford F-250 7-Way

Published 02/28/2019

Products Featured in This Question

Hook Probe Circuit Tester

(72)

$13.14

10 Gauge Wire - Blue Primary - Per Foot

(109)

$1.61

40 Amp In-Line Circuit Breaker - Perpendicular Mount Bracket

(101)

$9.99

Question:

2017 Ford F-250 platinum 6.7 camper package. No 12 volt charge power in truck 7 way plug receptacle. Testing with a meter. All other lights work fine. dealer said no mods needed, should work fine. Tested with engine on, and touched the brake also. Ford manual say trailer has to be connected to truck , truck will see connection and after that I need to touch the brakes to send power to the 12 volts power charge line. H I checked the #27 fuse and not there so I replaced bought a # 37 relay and it won’t seat, like there’s nothing holding it in??

asked by: Nate H

Expert Reply:

Activating the 12 volt accessory circuit of some vehicles can be confusing and challenging to get sorted out. What I typically recommend is to bypass the factory wiring and to run your own circuit so that you know it will be active. To do that all you have to do is use 10 gauge wire like part # 10-1-1 (sold by the foot) through a breaker like part # 9510 from the 1:00 pin on the 7-way to the positive post of your battery and you'll be set.

Otherwise you'll have to keep bugging Ford to figure out how to get the circuit to activate using factory wiring.

expert reply by: Jameson C