Hook up so you don't destroy your brake controller

Discussion in 'Tow Vehicles, Hitch & Towing' started by Indianrock, Aug 26, 2016.

  1. Indianrock

    Indianrock Member

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    Hi all. I recently had a Tekonsha brake controller installed on my Ford Ranger and could have sworn I read that you MUST install the battery on the trailer before plugging into the Truck. The result was destroyed brake controller. Looking at the manual now I see a warning about not testing the break away switch with the trailer plugged into the truck. This seems like a poor design if you can so easily blow up a $100 brake controller. Did I miss something?

    https://www.etrailer.com/Brake-Controller/Tekonsha/TK90160.html
     
  2. Yak

    Yak Well-Known Member

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    I'm not sure how these work, but if you pull the pin you back feed with 12+ volts
     
  3. tombiasi

    tombiasi Well-Known Member

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    Can you show the quote from the manual? I would like to see how it is worded.
     
  4. gruss

    gruss Active Member

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    Did you install the battery with the breakaway pin pulled? There is a warning on the controllers that they can be damaged if the breakaway is activated but if hooking up the battery fried it then you have bigger issues . I'll take a fried controller over totaled trailer everytime.

    Sent from my SM-G930V using Tapatalk
     
  5. Indianrock

    Indianrock Member

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    Sorry. I haven't destroyed the brake controller, just making sure I don't. I think the manual makes two points. 1) don't reverse battery connections -- and I take that to mean on the truck or the trailer. and 2) don't test the breakaway with the plug attached to the truck.

    I have my trailer battery cables marked since they're pretty much the opposite of everything else in the world I've encountered. Here, white is ground/negative and black is positive. Beyond that I just need to make sure I never test the breakaway with the trailer plug attached between truck and trailer.

    So if you did have the trailer break away from the truck on the highway, and the breakaway disconnected before the electrical plug, you might still ruin the controller. Probably not your biggest concern at that point. Now there is one old circuit breaker in the leads to the trailer battery and I know they installed at least one under the hood when putting in the controller. Not sure if either of those would help you or not.
     
  6. Nandy

    Nandy Active Member

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    I recall reading that, it dont say it will toast it for sure but you have a chance. As a matter of fact, i did that same thing and not a few seconds into my stupidity I recalled that warning and put the plunger back in. Controller is still fine working as usual, also, my brake away battery is one of those 4.5 amp/h battery that you commonly use for corn feeders and such...
    If you are really worried you can install a high amp diode and it will prevent the back feed from the brake away. You will need to do testing before and after the diode. You will loose an average of .5 volts from the controller but if you have a tekonsha I will think all you have to do is to increase the power to compensate.

    Good luck!
     
  7. Haybale

    Haybale I'd rather be camping!!

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    The simple fix would be to install a properly sized diode on that wire. A diode is simply an electrical version of a check valve.
     
  8. dion

    dion Member

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    But if you try that, be absolutely sure that you properly size it for the maximum load, and give a generous "fudge factor". An undersized diode will fail open circuit, and if that happened, you would be left without brakes.

    Furthermore, even a correctly functioning diode will result in a voltage drop, typically around 0.7V. This will reduce the amount of braking force provided. I suppose your calibration of the brake controller could account for this.

    The diode does seem like a reasonable idea, but on safety critical systems, I personally prefer not to get too clever, but instead to leave things simple and in stock configuration.
     
  9. tombiasi

    tombiasi Well-Known Member

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    I have yet to see where the manual says this can happen.
     
  10. Nandy

    Nandy Active Member

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    The warning about the breakaway is in the primus iq manual.
     
  11. tombiasi

    tombiasi Well-Known Member

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    OK thanks. I don't see such warning on my P3.
     
  12. Nandy

    Nandy Active Member

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    Maybe the P3 has a built in safety for that, interesting, so there is one more difference to add between the Primus iq and the P3 than what thought... For some that would be enough to pay the $50 difference...
     
  13. turborich

    turborich Active Member

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    I've installed a lot of the Primis IQ controllers and have never ran into this problem. Pulled a lot of break away switches as well. Not sure what's up with this? [2C]
     
  14. Nandy

    Nandy Active Member

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    They say there is a chance, not that it is a sure thing. Knowing this I would not pull that pin unless I get a case of brainfarts again....
     

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