New Expedition with trailer brake controller problems - Help

[CVille_Brian]

First post here - I'm looking for some help. Last week I purchased a new 2019 Expedition Max Platinum with Heavy-Duty Trailer Towing Package. Currently getting no power to the 12v lead or the trailer brakes. Anytime I squeeze the brake controller the Expedition screen reads, "trailer disconnected". I took it to the local Ford dealer for warranty work, but the mechanics weren't able to solve the problem. After a day in the shop they told me to wait 60 seconds after connecting the trailer, before adjusting the gain, or manually testing the brakes with the brake controller - this obviously didn't make a difference. I also tested the trailer with my Chevy pickup and it worked great. Also had the trailer inspected at a trailer shop. The trailer is not the issue.
I've performed a few trouble shooting steps and have ran out of ideas. I've checked the fuses in the engine and passenger compartment. I've tested the 7 pin trailer socket by testing it in another truck and testing a known functional trailer socket in the new Expedition - the socket isn't the issue.
Not sure what to do next. We hope to hit the open road with our travel trailer and Expedition next month.
I'd love some help here. Thanks in advance!

 

[Lou Hamilton]

Are you testing at the receptacle at the rear of your Expy?

It could be a bad part or loose wire inside.

I think the 12v power port fuse is #30, if my notes are correct. Make sure it is could and seated correctly.

 

[CVille_Brian]

Hey Lou, thanks for the reply. I tested at the 7-pin plug with a ABN 12V 7 Way Flat Pin Connector Tester. You're right about the 12v fuse being #30 - I checked that - the fuse is there and seated correctly.
If there's a loose wire, that exceeds my DIY capability. I reached out to a rural Ford dealer that is hopefully more capable of dealing with trailer controls.

 

[Lou Hamilton]

Hey Lou, thanks for the reply. I tested at the 7-pin plug with a ABN 12V 7 Way Flat Pin Connector Tester. You're right about the 12v fuse being #30 - I checked that - the fuse is there and seated correctly.
If there's a loose wire, that exceeds my DIY capability. I reached out to a rural Ford dealer that is hopefully more capable of dealing with trailer controls.

Good luck! Hope you find something soon and safe travels.

 

[Frank Swygert]

It's a 2019, still under warranty. You did what I was going to suggest -- try another Ford dealer. They just don't want to put in the time to fix it since they don't get much for warranty work and electrical issues can be hard to track down.

Power at the 12V lead would be easy enough -- run a new wire. But no power at the trailer brakes (should be only with brake pedal pushed) sounds like a brake controller issue. There should be a fuse for the controller itself, check that as well.

 

[CVille_Brian]

Problem solved (after two dealers and three full days in the shop).

The trailer brake issue was the result of a faulty harness that houses the trailer brake controller. It simply needed to be replaced.

12v lead - The vehicle computer is smart enough to discern the difference between an actual trailer and a 7-way circuit tester. When plugging in a circuit tester, the vehicle will not recognize a trailer connection and subsequently will not switch on the 12v auxiliary feed. The 12v auxiliary feed also does not turn on, at least initially, until you put the vehicle in drive. We verified this by connecting to a horse trailer, without a battery, that has ceiling fans powered by the 12v feed from the vehicle. Only after the trailer was connected and the vehicle was in put into drive, could we power the fans and verify a 12v auxiliary current. Of the handful of Ford mechanics and subsequent trailer shop mechanics, no one seemed to be aware of this. Ultimately, an electrical engineer and a trailer shop owner helped me figure this out.

 

[Robert Stucky]

Out of curiosity - we had similar issues with the trailer brake controller. No power unless driving. But we also had NO brakes below 15 mph. Manual says that braking will be reduced below 15, but we had none. Tried on multiple trailers including one at the dealership. Ford Engineering responded that is was designed that way - which can't be right.

Curious how your low speed breaking works.

We ended up having the dealer take the vehicle back - not paying that much $$ for a vehicle that doesn't work.

Considering trying again, possibly with an aftermarket controller as there aren't any other viable options (that we've found) built in this decade for hauling a 30' 7,000 lb rv trailer and have 3 Saint Bernards in the truck.