2017 Ford F-350 7 Pin Trailer Connector

Question:

My 2017 Ford F-350 with its factory installed 7 pin trailer connector will not charges or power the 12 volt system of my 2014 35’ Cedar Creek Silverback fifth wheel trailer. We hooked my daughters GMC Acadia to the same seven pin plug and the 12 volt system worked just fine. So we know the trouble is with the truck. What do I need to do?

asked by: Cindee S

Expert Reply:

First I recommend double checking that you setup your trailer in your truck, by naming it on the information screen after hooking up the trailer. Your truck has a smart tow feature that will not send power to the 12v auxiliary power pin until the trailer is setup.

If you are still not getting 12v auxiliary power in the factory 7-way connector I recommend checking that fuse 27 is not blown or missing in the engine compartment fuse box. This should be a 30 amp fuse and controls the 12v auxiliary power pin.

If your truck does not have the factory trailer brake controller I also recommend checking that relay 37 is not missing.

If the correct relay and fuse is in place and not blown then you will trace the power wire running from the 1 o'clock position of your 7-way to the front of your truck looking for any damage causing the issue. You can use circuit tester # PTW2993 every few feet to see if there is a dead spot in the factory wire.

If you cannot find the damage in the wiring then you can bypass the factory circuit by using # 10-1-1 which is sold by the foot to run from the 7-way connector to a 40 amp circuit breaker # 9510 and then to the positive terminal of your battery. You will also need heat shrink butt connectors # DW05745-5 and two ring terminals # DW05705-1.