Brake pedal not showing power on 7-pin Trailer hookup, possibly easy fix?

[Mylriahd]

I just bought my 2021 last month, and now that I am just over 1000 miles I am planning on renting a travel trailer next week. This is my first time towing, so I don't know how everything works quite yet but I decided to take a multimeter and test my 7-pin connector. All lights work as expected EXCEPT: When I step on the brake pedal I get no voltage from the brake pin. I DO get variable voltage as expected when I squeeze the brake controller manually, and I do get signal on the brake lights with the pedal. Only the signal to the trailer brakes appear to not do anything.

I hooked it up to a trailer and confirmed that the brakes barely engage when gain is set to +10 and full pedal.

Is there anything I can check / fix on my own? I have scheduled service anyway since we'll be crushed if we have to cancel a vacation because of this, but would love to know more about how this works so I can fix it on my own if it happens while on the road.

Thanks!

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[daemonic3]

Just a warning it *might* be working as intended. The truck knows to apply more braking when slowing down than when stationary. I have noticed this by watching the gain meter on the trailer screen on my 2017. The only way to know more is by hooking up and testing the stoppability with the particular trailer.

FYI mine is set to +8 and is over 7k pounds conventional trailer.

 

[Mylriahd]

Just a warning it *might* be working as intended. The truck knows to apply more braking when slowing down than when stationary. I have noticed this by watching the gain meter on the trailer screen on my 2017. The only way to know more is by hooking up and testing the stoppability with the particular trailer.

FYI mine is set to +8 and is over 7k pounds conventional trailer.

This is great insight; I will have to see if I can figure out how to test this. We're renting the trailer next week, but if it doesn't pass all of the checks they won't let me take it. If It's only applying signal based on movement, that would at least be easy to prove by hooking up and towing in the parking lot. Thanks for your response!

 

[Jus Cruisin]

You might need to adjust the trailer brakes? Some are manually adjustable

 

[Mylriahd]

You might need to adjust the trailer brakes? Some are manually adjustable

At this point I don't even have a trailer to try it on, I'm just using a multimeter and testing pins so I can solve problems before they turn me away when I go to pick up the rental. I'm looking for alligator clips to attach so I can test while moving to see if the suggestion about the voltage if there is resistance (motion) against the brakes.

 

[jimcam22]

When you hook up the trailer just squeeze the brake controller paddles and you should hear the brakes engage. Then pill forward slowly and squeeze the brake controller paddles again and you should feel the trailer trying to slow you down.

 

[Camptruck]

I DO get variable voltage as expected when I squeeze the brake controller manually

It sounds to me that it is working correctly based on the above statement. It is not pressing the brake peddle that applys the voltage to the trailer brake wire, it is the brake controller that does that. I can't say how the Ford brake controller works (1st time with a built in controller) but the after market brake controllers work by detecting/measuring the amount of deceleration being registered in the brake controller and applying voltage to the trailer brake wire accordingly. There are two types: 1) on/off (voltage applied or not); 2) proportional types that vary the voltage based on the amount of deceleration. Not sure which Ford uses, but given the price I am expecting the latter.
Squeezing the brake controller manually, forces the brake controller to apply voltage to the trailer brake wire.

 

[Mylriahd]

the after market brake controllers work by detecting/measuring the amount of deceleration being registered in the brake controller and applying voltage to the trailer brake wire accordingly. There are two types: 1) on/off (voltage applied or not); 2) proportional types that vary the voltage based on the amount of deceleration. Not sure which Ford uses, but given the price I am expecting the latter.
Squeezing the brake controller manually, forces the brake controller to apply voltage to the trailer brake wire.

Super helpful! This makes sense, and caused me to back up and ask what I should have asked to start with: "how do these things work anyway?" I had just assumed there was only the on/off style and decided there was a problem since I couldn't get a reading pressing the pedal. So I looked it up and this paragraph from the article pretty much explains what you said:

The newer proportional electric brake controllers on the other hand measure the changing momentum, or inertia, of the moving car via an accelerometer; they are not directly connected to the car’s brakes and work independently of them. Continuously monitoring the vehicles dynamics, these controllers send the precise amount of voltage to the trailer brakes to ensure that the speed of the trailer matches that of the tow vehicle. This generally makes for a smoother braking experience and more efficient braking, ensuring your trailer brakes last longer. For instance, when going downhill, you’ll want to engage lower gears to slow down in order to decrease brake wear; inertia-based brake controllers sense that the vehicle is slowing down (rather than the vehicle’s brakes being applied) and therefore adjust trailer braking power accordingly.

This says that my controller likely works exactly the way it should and maybe unfortunately most people wouldn't know it was broken until they were attached to a trailer. But I'm going to put the panic flag down and assume I'm good to go for next week. Hopefully this thread can help some future newbie.

Thank you!

 

[Camptruck]

Super helpful! This makes sense, and caused me to back up and ask what I should have asked to start with: "how do these things work anyway?" I had just assumed there was only the on/off style and decided there was a problem since I couldn't get a reading pressing the pedal. So I looked it up and this paragraph from the article pretty much explains what you said:

The newer proportional electric brake controllers on the other hand measure the changing momentum, or inertia, of the moving car via an accelerometer; they are not directly connected to the car’s brakes and work independently of them. Continuously monitoring the vehicles dynamics, these controllers send the precise amount of voltage to the trailer brakes to ensure that the speed of the trailer matches that of the tow vehicle. This generally makes for a smoother braking experience and more efficient braking, ensuring your trailer brakes last longer. For instance, when going downhill, you’ll want to engage lower gears to slow down in order to decrease brake wear; inertia-based brake controllers sense that the vehicle is slowing down (rather than the vehicle’s brakes being applied) and therefore adjust trailer braking power accordingly.

This says that my controller likely works exactly the way it should and maybe unfortunately most people wouldn't know it was broken until they were attached to a trailer. But I'm going to put the panic flag down and assume I'm good to go for next week. Hopefully this thread can help some future newbie.

Thank you!

You are welcome. That is what this site is all about. Helping each other.

 

[daemonic3]

Super helpful! This makes sense, and caused me to back up and ask what I should have asked to start with: "how do these things work anyway?" I had just assumed there was only the on/off style and decided there was a problem since I couldn't get a reading pressing the pedal. So I looked it up and this paragraph from the article pretty much explains what you said:

The newer proportional electric brake controllers on the other hand measure the changing momentum, or inertia, of the moving car via an accelerometer; they are not directly connected to the car’s brakes and work independently of them. Continuously monitoring the vehicles dynamics, these controllers send the precise amount of voltage to the trailer brakes to ensure that the speed of the trailer matches that of the tow vehicle. This generally makes for a smoother braking experience and more efficient braking, ensuring your trailer brakes last longer. For instance, when going downhill, you’ll want to engage lower gears to slow down in order to decrease brake wear; inertia-based brake controllers sense that the vehicle is slowing down (rather than the vehicle’s brakes being applied) and therefore adjust trailer braking power accordingly.

This says that my controller likely works exactly the way it should and maybe unfortunately most people wouldn't know it was broken until they were attached to a trailer. But I'm going to put the panic flag down and assume I'm good to go for next week. Hopefully this thread can help some future newbie.

Thank you!

Same thing I said earlier but in way better terms

I think you'll be fine, just start with the gain at +1 for every 1k pounds of trailer GVWR, then make adjustments from there in an empty lot.

There is another setting in the tow options that is something like "trailer braking" and I remember the choices as low/normal/high or something like that, and it was how quickly to apply the gain. That one is independent of the +/- gain adjust buttons on the squeeze trigger. I always kept mine set to normal or default. But just want to note that is NOT the gain setting itself.

 

[Mylriahd]

Same thing I said earlier but in way better terms

I think you'll be fine, just start with the gain at +1 for every 1k pounds of trailer GVWR, then make adjustments from there in an empty lot.

There is another setting in the tow options that is something like "trailer braking" and I remember the choices as low/normal/high or something like that, and it was how quickly to apply the gain. That one is independent of the +/- gain adjust buttons on the squeeze trigger. I always kept mine set to normal or default. But just want to note that is NOT the gain setting itself.

I recognized that this is what you were saying in your first post now, I just didn't understand it yet.

It's a good callout about how to set gain, the only thing I've read was "just keep increasing until the trailer is noticeably pulling on you" which doesn't tell me a good starting point.

For Tow options, I'll have to play with those, it sounds like those options could be the difference between comfortable towing and "something feels off".

 

[Matt604]

I think i've got a slightly different problem with my brake controller on a Plat w/ Tow Package that i picked up last week. With trailer all hooked up, brake lights and turning signals on trailer working correctly via the truck, but squeezing the brake controller switch manually does not engage the trailer brakes. There is no sound of them clicking or humming on, the graphic on the dash does show up but as 0 or blank gain and never changes. This is on a 23' tt taken out of winter storage but was in full working order brake wise before. I previously used an add-on Prodigy P2 brake controller but for my new truck the 'setup' was to plug in the cable to the receptacle near the hitch. I did play with the brake type and gain sensitivity settings which made no difference.

I'll get it booked into service asap so i can tow this weekend but crossing fingers it won't be a back and forth thing requiring me to bring in my trailer too.

Did i miss anything simple that could be the problem?

 

[SuvE]

Broken wire on trailer?

 

[BoostedECO]

Broken wire on trailer?

 

[BoostedECO]

I’m having the same issue as Matt604. I set the gain to 10. And nothing. Trailer is 3500lbs They say in the owners manual to drive 20to25 set the gain use the switch manually if they lock up back off. Did that at 10 and nothing. Had a 18’ I towed with last year never had an issue. Any help would be appreciated suppose to go camping this weekend.

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