Trailer breaks not working

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Feb 5, 2018 | 08:56 PM

Scott Taylor

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Joined: Feb 2018

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Trailer breaks not working

I have a 2017 F250. When I plug a trailer plug into the 7 pin The truck recognizes the trailer. However the trailer brakes do not work and the 12 V power does not work the trailer lights all work perfectly. I have had it at the Ford dealership for hours and they are at a loss they are telling me that they are hearing this is a common problem does anyone have any information that could help? I just recently put a programmer and exhaust on my truck just wondering if that could be a problem not sure why it would matter though. Any help would be greatly appreciated as I pull with this truck a lot. By the way I did check the truck on multiple trailers also check each trailer with other trucks just to make sure the truck was not working.

Feb 6, 2018 | 01:39 PM

KentuckySteve

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Joined: Jan 2018

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Fuse?

I'm sure you or the dealership checked the fuse, but I was told from my dealer that a bad fuse is a big issue with the trailer connection.

Feb 6, 2018 | 01:49 PM

troverman

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Joined: Apr 2013

Posts: 10,118

Likes: 650

From: NH

I've had more problems with the 7-pin on my 2017 Super Duty trucks than with the previous generation of Super Duty truck. The problem I've had is the contacts become dirty and corroded. It usually causes me lighting issues as well. If the dealer has already worked on it, they've likely cleaned the contacts and this may not be your problem.

Feb 6, 2018 | 05:00 PM

K A M

Senior User

Joined: Apr 2005

Posts: 471

Likes: 4

Several things to check, type trailer brakes are selected and at proper setting and is the gain set

Feb 7, 2018 | 10:09 AM

stewy604

Elder User

Joined: Aug 2017

Posts: 703

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Trailer wiring can definitely be a PITA sometimes. I know on my equipment trailers, the electric-hydraulic brakes won't function properly if the trailer battery is failing. Maybe start there?

Feb 7, 2018 | 11:43 AM

K A M

Senior User

Joined: Apr 2005

Posts: 471

Likes: 4

Maybe see if you can hook up to another trailer to test. This will tell you if it's the truck or the trailer.

Feb 7, 2018 | 01:07 PM

tubaphysics

Freshman User

Joined: Mar 2017

Posts: 37

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From: Iowa

This might seem like a dumb question, but it got me at first, how do you know they are not working? On my 2017 F350 when the brake petal is depressed while in park the brakes on the trailer will not engage. However, the slider will still engage them.

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Feb 7, 2018 | 10:51 PM

Flyct

FTE Community Team

Joined: Mar 2017

Posts: 3,337

Likes: 1,050

From: Florida

The Ford OEM trailer brake controller is unique.

Prior years required a relay installed but the 17 does not. It uses logic to turn on the trailer brakes.

Here’s my understanding of how it works.
The 7 pin plug needs to be connected. Then you must drive more than 15 mph before hitting the brake pedal to activate the trailer brakes. They will continue to remain activated all the way to a stop. If you stop, take your foot off the brake pedal and just drive very slowly the trailer brakes will not activate. This is to prevent jerking when brakes are applied while maneuvering to park.

I have Electric over hydraulic disk brakes on my RV. I can hear the hydraulic pump run. When I stop at a light after slowing down I can hear the hydraulic pump running. If I let off the brake pedal and reapply it and i can hear the pump stop and remain off.