2017 New truck says 5th wheel it not connect? Update 2-14-18

Similar problem with my trailer. After much trouble shooting I found that a taillight mounting bolt had been over tightened during assembly causing the inside metal connections behind the bulb holder to be twisted over and touching one another.

Adjustment was made resulting in no more dash error messages.

Good luck.

Lakeside

The only LED lights on an F350 dually are the roof lights and rear fender/center marker lights. All others are incandescent.

Had a similar problem with trailer lights not being LED. The UPFITTER Module will think there is a short. I replaced all lights on trailer and this solved the problem. The new truck are so much better with all the protection for both truck and trailer.
Similar to "KERRLAKEREO" response.

wrvond wrote:
If you have the umbilical plugged in and the truck is able to test the lights, then everything should work.
Have you tried plugging the umbilical into both outlets?

I have seen one case where the female plug on the truck came from the manufacturer incorrectly wired.

I didn't know Lippert was making trucks, now!? :B

Lyle

If you have the umbilical plugged in and the truck is able to test the lights, then everything should work.
Have you tried plugging the umbilical into both outlets?

I have seen one case where the female plug on the truck came from the manufacturer incorrectly wired.

If at all possible I would check with the dealer to see if there is an update available for this system. I used to have a 2015 F150 that needed an update after pulling a smaller trailer with trailer brakes. After updating the trailer brake control module in the truck we had no more issues.

A bad ground connection explains the vast majority of trailer wiring problems.


X2

Has this problem been there every since buying the new truck? Or did it just start?
With the new truck likely having LED lights, and the trailer having old style Incadescents it could be trying to draw too much and making your display think there is a short.

Chuck .. wrote:
2017 350 Ford daully....I step on the brakes the dash reads out and says that the left and right tailor lights not working/fault.

The right and left turn signal flashes rapidity when turned on. Also it says that the trailer is not connected.

#1 GROUND
Check all ground connections:
** truck 7-way
** Trailer umbilical
** Trailer brake leads
** Trailer lights

A bad ground connection explains the vast majority of trailer wiring problems.

#2 Trailer Brake wiring
Trailer manufacturers are notorious for cheap wiring of the brakes. Most often they daisy chain all the brakes together and run leads through the axle tubes. The daisy chain connections typically use scotch lock connectors which are great at corroding or not fully penetrating the wire insulation. Also the wires running though the axle tubes are famous for getting chaffed and causing a short to ground.

Usually when I've seen "Trailer Not Connected" it means there is a fault in the brake wiring connection. I've seen it twice in my RAM pulling 2 separate gooseneck trailers I had borrowed. One was really trashy wiring with corroded and broken connections. The other was because they had used non-standard wiring patterns in the trailer 7-way connector. Previously in my old truck I got NC (not connected) errors with my Prodigy brake controller. That issue was related to bad OEM brake wiring on the trailer.

KJ

Don’t forget to check under hood fuses for trailer towing