No Brake Lights or Turn Signals on Factory Trailer Plug on 2019 Ford F-350 Super Duty

Updated 12/30/2019 | Published 12/27/2019

Question:

No power to trailer plug for both turn and brake lights message says no trailer connected checked in fuse panel space 72 fuse is good need to purchase a mirror to see fuse in space 24 was wondering if you might have any other suggestions thanks

asked by: Robert D

Helpful Expert Reply:

The fuses are always a good place to start in this situation, and since this is a new truck, I don't believe that the actual plug is going to be defective in this instance. The other thing I would recommend checking is the connection under the truck that connects the US car connector to the 7 way plug- make sure it is firmly connected and that there is no damage to any of the wiring (also check the ground). You'll want to make sure that the truck is on and you've tapped the brakes since there is a protection on the trailer brake monitoring module that will only allow the circuits to power with the truck on and a brake signal sent.

From my research, it looks like there are a couple of other fuses that can be checked that affect the trailer wiring:

#54 (30A, Trailer brake control module)
#72 (30A, Trailer tow LH/RH stop/turn)
#84 (10A, Trailer back up lamps)
#99 (30A, Trailer tow parking lamps)

If you can verify the status of the fuse in slot 24 and that your truck's wiring at the back of the 7 way is in good working condition and this still has not been resolved, please let me know and I will continue to troubleshoot.

expert reply by: Erik B