Forum Discussion

Powerstroke2000's avatar
Powerstroke2000
Explorer
Mar 29, 2015

7 way trailer plug issue...

I have an '09 Ford F450, and I've got an 'ongoing' trailer brake issue. I've taken the truck to my local Ford dealer ($100.00+ to check) and said they could find no problem, but if it still doesn't work, take the truck and trailer to a trailer repair place...so, that I did. $75.00 later....after having to run the truck there, and then go again and pick it up later in the afternoon....and they tell me there is no problem. Still....no brakes coming on on the trailer with the service brakes, only if I pull the slide on the integrated brake controller. So, this same trailer repair place has another outlet in another town, which is about an additional 20 minutes further, but I thought I'd give them the benefit of the doubt...and again, hauled my truck/trailer out there. They check it all out, pull the wheels on the trailer (since it was there anyway) and checked the brakes and greased the bearings. They say all is good....but still, I'm not feeling anything when I push the brake pedal on the truck. The trailer has now sat all winter, and I'll need the trailer in a month or so....so I went out and bought a Tekonsha "trailer emulator", which you just plug in to the 7 way plug at the rear of the truck! Looked up a 'how to do' on Youtube, and sure enough, found a couple of video's on how to use the emulator correctly. When I turn the ignition key to 'on'....I should get a 12v signal light to come on...but I get 'nothing'. Left and right turn signal emulation works just fine. Brake light emulation works just fine. Putting the truck in reverse, I should get two bottom LED's to come on....I get 'nothing', albeit the bottom middle light flickers off and on about every 4 seconds.
Needless to say...I think it's a 'truck' issue now, and I'm wondering if it's the actual integrated brake controller (doesn't sound like this is an issue after researching the issue...as of yet anyway), or the 7 way plug attached to the truck?
This all makes me wonder though....why FORD and 'twice' the trailer repair shop didn't find this same issue? I'm now out about $200.00 plus.....and I had to figure out this on my own!

Anyone have any advice on if they think I should just replace the 7 way plug, or could it possibly be another electrical issue? I am having on other issues with the truck other than this. I had the integrated trailer brake controller at 8.5 (which is high) and still got no trailer brake coming on. The trailer 'lights' come on when I push the brake pedal...just no brakes coming on to slow the trailer! They 'use' to work just fine, and would even hear the odd screech of the tires if the controller was too high....but now I get nothing.

Thanks in advance!
Seeking Advice
  • Bipeflier's avatar
    Bipeflier
    Explorer
    Apr 03, 2015
    Logic tells me that:
    1. Since the brakes work with the manual lever application, the 7 way plug and trailer brakes are fine.

    2. Since the manual control lever works, the wires and fuses are fine.

    3. If you can't adjust the brake controller gain any higher the controller is suspect.
  • JLTN_James's avatar
    JLTN_James
    Explorer
    Apr 02, 2015
    Terryallan wrote:

    Except for the useless timed brake controllers, MOST electric Brake controllers Prodigy, P2, Voyager, and the Ford, ect are Inertia activated, Meaning the trailer has to be moving for the brake controller to activate the brakes.


    My Prodigy (inertia based) provides a constant voltage at 25% of the setting when stopped. This is to engage the trailer brakes to hold it in place, such as when on a hill. I'm sure the later generations based on the Prodigy have this feature.
  • CavemanCharlie's avatar
    CavemanCharlie
    Explorer III
    Apr 01, 2015
    gijoecam wrote:
    The Ford integrated controller is not inertia-based on the '08(I think?) and newer trucks. It uses a pressure signal from the brake system to proportion the brakes to the trailer based on the bias setting.

    The system needs three inputs: The brake pressure switch, brake pedal position switch, and the brake pressure transducer.

    I don't understand why the dealership can't figure it out... They can scan the TBC inputs, and at the connector, they can monitor the outputs. Skimming over the troubleshooting manual, it shouldn't take them more than a half hour to sort out the problem, honestly. If you've had it in three times, their techs are incompetent and you need someone experienced to sort it out.

    But, start with the basics: Battery junction box fuse #5 (30A), Smart Junction Box (under the dash) #33 (10A) (I doubt it's either, but you ALWAYS have to start with the basics)

    They connect the scanner, check for codes, and go from there. My guess is that if there are no codes in teh system, there is a compromised wire or pin in a connector somewhere between the TBC in the dash and the back of the truck. Again, they have detailed instruction on how to find it in the troubleshooting and diagnostics manual. They just need to take the time to do it, plain and simple.

    Good luck!!


    I wouldn't go that far. On these newer computerize vehicles sometimes there is just no fixing.

    My brother had a brand new truck that would run fine except when towing his 5th wheel down the interstate. Then it would act up and suddenly not go over 45 mph. He took it to 4 different dealers in two different states and they never could fix it. He ended up trading it in just to get rid of the problem.
  • kmbelt's avatar
    kmbelt
    Explorer
    Mar 31, 2015
    Hook up to trailer, plug in 7-way.

    Crank truck brake controller to higher setting and do a test to see if the brakes grab before the trucks do.

    On all of my previous trucks, i could crank it all the way up and when i hit my brakes, I knew they were working as it tended to jerk the truck back a little.

    If yours does this, then the stuff is working and just needs to be fine tuned.
  • gijoecam's avatar
    gijoecam
    Explorer
    Mar 31, 2015
    The Ford integrated controller is not inertia-based on the '08(I think?) and newer trucks. It uses a pressure signal from the brake system to proportion the brakes to the trailer based on the bias setting.

    The system needs three inputs: The brake pressure switch, brake pedal position switch, and the brake pressure transducer.

    I don't understand why the dealership can't figure it out... They can scan the TBC inputs, and at the connector, they can monitor the outputs. Skimming over the troubleshooting manual, it shouldn't take them more than a half hour to sort out the problem, honestly. If you've had it in three times, their techs are incompetent and you need someone experienced to sort it out.

    But, start with the basics: Battery junction box fuse #5 (30A), Smart Junction Box (under the dash) #33 (10A) (I doubt it's either, but you ALWAYS have to start with the basics)

    They connect the scanner, check for codes, and go from there. My guess is that if there are no codes in teh system, there is a compromised wire or pin in a connector somewhere between the TBC in the dash and the back of the truck. Again, they have detailed instruction on how to find it in the troubleshooting and diagnostics manual. They just need to take the time to do it, plain and simple.

    Good luck!!
  • Kit_Carson's avatar
    Kit_Carson
    Explorer
    Mar 29, 2015
    Have you checked all the grounds?? A friend was having a similar problem and found the ground under the fifth wheel was not making good contact. Cleaned everything real good and reinstalled and all is well.
  • Houston_Remodel's avatar
    Houston_Remodel
    Explorer
    Mar 29, 2015
    I too will add "check the fuses" It seems simple, but we've all chased similar problems. Lord knows I have.

    I found out my F150 has a fuse inside the truck for the trailer left turn signal. Whodah thought ?
  • CavemanCharlie's avatar
    CavemanCharlie
    Explorer III
    Mar 29, 2015
    Are you sure it's not working when you are moving? If set up correctly it should work so well that you may have a hard time telling the difference in braking from when you are not towing.

    Find a safe place where you don't need taillights. Then stop with the connector plugged into the truck and measure the distance. Then unplug the connector and do the test the same way again and measure the distance.

    Maybe it's working and you just don't know it.
  • dcb17b's avatar
    dcb17b
    Explorer II
    Mar 29, 2015
    I do not know anything about the built in brake controllers but just to throw it out there: can you turn up the braking power? I see there is a + and- which I assume(yeah I know) is to adjust the amount of braking applied.
  • Terryallan's avatar
    Terryallan
    Explorer II
    Mar 29, 2015
    I know you have checked. But gonna say it any way. Check the fuses, and relays to be sure they are installed in the right places to send power thru the brake lights to the trailer.

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