I’ve just discovered there is no power to the +12v pin on the 7 way connector, so the truck will not power EOH brakes. My truck has a trailer tow package with a built in brake controller, and EOH is selectable on the My View panel. But after two weeks at the dealership I’m told it simply wasn’t built to provide power to that pin and there’s nothing they can do about it.

Anyone else run run into This?

 

Your dealer is uninformed. The 12v pin is only active when a trailer is attached and you have either depressed the brake or slide the brake controller manually once. Testing with no trailer attached will show no 12v. The pin is turned on electronically after the truck senses trailer brakes connected...

 

x2 what Rodney said.. Here's the SSM46212

"All 2017 F-Super Duty vehicles equipped with a factory trailer brake controller (TBC) utilize a trailer module (TRM) which initiates the trailer charging system. For trailer charging to operate, the TRM must detect a trailer is connected and a brake pedal input before charging will be present at the trailer connector. Adding the trailer battery charge relay and fuse into the battery junction box are not required to operate trailer charging with a TRM. If testing of the trailer charging system is required without a trailer, refer to the updated diagnostics and system operation found in the online Workshop Manual (WSM), Section 417-01 Exterior Lighting."

 

Alternatively, you could convert your 7 way charge pin to always hot if so desired. I'll attach a doc to describe how to do it to this post.

 

There may be certain EOH brakes that may not be compatible with the built in controller. I am not an expert but ran into this with my GM truck. Had to add an aftermarket or some sort of magnets to the EOH trailer side controller. Had to do with the pulsing of the voltage if I remember correctly.

 

Thanks, guys, this is very helpful. I showed this to the techs yesterday when I picked up my truck and they said yes, it could be the system is operating ok and I'm just not meeting all the conditions required for the trailer module (TRM) to initiate charging voltage to the pin.

I'll certainly look into installing the jumper wire on the module to bypass all this silliness.

Wish me luck!

Cole

 

I found that the TRM needs to sense both trailer stop / turn lamps before it will allow initiation of the +12 circuit. Our slide-in truck camper doesn’t have stop / turn lamps, so I use an LED trailer lamp load adapter to “fool” the TRM. The adapter plugs in series within the 7-pin harness.

Example:

HTH,
Jim / crewzer

 

Thanks, Jim, but Amazon says it doesn't fit my 2017 F350. I take it, though, you're using it with no problems?

Cole

 

Amazon is run by idiots. The 7-pin connector standard doesn't belong to Ford. That thing fits every flat blade 7-pin connector on the planet.

 

Cole,

I’ve successfully used the Curt adapter several times on both our 2017 and the 2019. Here’s a picture of it plugged into the 2019.





Also check out the Towready #20142 adapter. I have one, but I haven’t yet verified its functionality.

HTH,
Jim / crewzer

 

The curt adapter is great if you are using a tester to verify the plugs are working. It takes the truck Into thinking a trailer is connected. My 2017 450 didn’t have the resistor in one fuse slot nore the fuse in another, so the dealer told me I needed both. Turns out I needed neither, just to tap the brake and squeeze the controller once connected to energize the plug. Funny that the service people don’t know this when you ask them.

There is a fuse in slot 65 that will blow from time to time...keep extras of those available. It otherwise if you have the factory installed controller you are good to go.

 

Just in case this might help:

https://www.ford-trucks.com/forums/1...-of-truck.html

 

I have been towing RVs for over 30 years with various Ford trucks--in my opinion, 90% of Ford shops know very little about truck/trailer hookups. Way more knowledge on this forum.

 

Has anyone tried this fix on a F250? I checked the voltage on the connectors, and the "green/red" wire, which is RED on my F250, does not have 12 volts on it. But the other wire on that connector does. I didn't connect to it, because I can't tell if that is really correct.

 

My problem was finally solved by a knowledgeable tech at a little country dealer where a lot of people tow trailers. It was a bad fuse in a mislabeled slot in the fuse panel located under the hood. I have since corrected my owners manual to indicate the correct slot.

Cole