Forum Discussion

js415's avatar
js415
Explorer
Oct 11, 2019

Trailer Brake issues.....

I'm towing a 2017 Heritage Glen 300BH, with a 2006 Silverado 2500HD, Duramax/Allison combo.

Dual axle, and I use a Prodigy P2 controller.

I've been towing this trailer for about a year with no issues. This summer, I started developing a loss of brakes while driving, and I would get a "OL" message on my controller.

Research tells me that it is probably a short somewhere. The brake circuit rubbing on the frame or inside the axle.

I can still apply and use the brakes manually when this occurs.

Today I pulled the wire out of the axles expecting to find worn spots. The wire was in perfect condition.

I went ahead and replaced it with 12AWG wire and tapped it all back together. We plan on leaving again this coming Thursday so that will be my first time to test.

I was shocked at how small the wire was inside the axle. It could not have been larger that 24 gauge wire. Is it possible the wire was just so darn small that it was causing the overload condition?

My next plan is to pull it this week, see what it does after a few miles. If it starts again I will cut the brakes to one axle to see what happens. If it continues, hook that axle back up and cut the other axle.

If it still continues, where the heck do I go next. Try and eliminate one assembly at a time?

Any other areas you folks have found problems?

Thanks for any advice,

Jerry
  • ScottG's avatar
    ScottG
    Nomad
    Oct 11, 2019
    No, small wire wont cause an overload message. Basically the +12 has to be shorted to ground someplace for the P2 to show that.
  • time2roll's avatar
    time2roll
    Nomad
    Oct 11, 2019
    Grab your clamp-on DC ammeter and check each wheel is getting about 3 amps when controller is applied manually. Then reconcile with the amps coming out of the controller.
    No meter? Good excuse to buy a new tool ;)
  • Old-Biscuit's avatar
    Old-Biscuit
    Explorer III
    Oct 11, 2019
    ScottG wrote:
    No, small wire wont cause an overload message. Basically the +12 has to be shorted to ground someplace for the P2 to show that.


    YEP^^^^^^

    Short...
    Can be at umbilical cord, plug, receptacle
    Can be at Emergency Break Away Switch
    Can be at ANY of the brake magnet connection
    Can be INSIDE the drum where magnet wires have rubbed against shoe lever arm

    OR bad GROUND
    Check the brake magnet ground wire connections
    Check umbilical cord plug/receptacle for corrosion
  • js415's avatar
    js415
    Explorer
    Oct 11, 2019
    time2roll wrote:
    Grab your clamp-on DC ammeter and check each wheel is getting about 3 amps when controller is applied manually. Then reconcile with the amps coming out of the controller.
    No meter? Good excuse to buy a new tool ;)


    I'm not sure that will work. I can sometimes drive 20-30 minutes without the error message. Then sometimes I pull over to an exit ramp and it does it all the way up the ramp.

    With it being intermittent, would a amp meter reading tell me anything conclusive?

    Thanks,

    Jerry
  • js415's avatar
    js415
    Explorer
    Oct 11, 2019
    Old-Biscuit wrote:
    ScottG wrote:
    No, small wire wont cause an overload message. Basically the +12 has to be shorted to ground someplace for the P2 to show that.


    YEP^^^^^^

    Short...
    Can be at umbilical cord, plug, receptacle
    Can be at Emergency Break Away Switch
    Can be at ANY of the brake magnet connection
    Can be INSIDE the drum where magnet wires have rubbed against shoe lever arm

    OR bad GROUND
    Check the brake magnet ground wire connections
    Check umbilical cord plug/receptacle for corrosion


    I've pulled 2 other trailers this summer for over an hour each and did not have any issues with them. Leading me to believe it is on my trailer.

    I have not looked at breakaway switch. Gonna do that this evening and see what it looks like.

    After I narrow it down to an either an individual axle, or something else, I can at least start looking in the right direction, if it is a magnet/wiring related issue.

    Thank you,

    Jerry
  • js415's avatar
    js415
    Explorer
    Oct 11, 2019
    I've looked at my breakaway switch and not happy with it. The wiring all looks good, but the plastic housing is cracked and split apart.

    Even though, that should not cause the issues I am having, I do not believe. Unless some of the wiring inside the case is rubbing on something. I've ordered a new one and can replace it Sunday.

    Jerry
  • Gdetrailer's avatar
    Gdetrailer
    Explorer III
    Oct 12, 2019
    This isn't brain surgery..

    Make your life simpler and just scrap the existing brake wire run from front to the axles and be done with it. The factory often uses too light of wire to start with and it is not worth the hassle to attempt to find the intermittent short in it.

    Replace the existing wire by upgrading the wire ga 12Ga minimum but larger can often make a huge improvement in your brakes, your brakes will work better than new.

    You do not need to find and remove the OEM wire, just cut it out on both ends then run the new wire along the trailer frame.

    While doing that pull each brake drum and inspect the magnet wires, they often get tangled inside the drums with the mechanical arms and damage the insulation which can cause intermittent overloads.
  • ajriding's avatar
    ajriding
    Explorer II
    Oct 12, 2019
    Agree with just running completely new wire. 12g or 14g should be fine, but do use bigger wire than the factory did, it might matter, it might not, but wont hurt. I used speaker wire from HD.

    When I redid my last trailer I also made all the wire connections inside a storage box and not outside under the trailer, this keeps the wires and open ends dry and safe.

    The magnets do go bad sometimes, and will eventually fail after many years. For just a one year old trailer maybe not start there, but old trailers it is just easier to replace all the magnets while you are messing with it all. They will fail. etrailer.com has all your solutions, and you can email them for pro answers too, there is a "chat" box on their site.
  • js415's avatar
    js415
    Explorer
    Oct 12, 2019
    The existing "home run" wiring is encased in a wire loom from the trailer tongue to the first axle.

    This is then completely covered by the coro-plast material that covers the bottom of my trailer. While not impossible, it would be quite a job to replace unless I can pull it out of the wire loom in one whole section while pulling new wire in.

    I bought a 100' roll of 12/2 wire. That is what I used for the new wiring at the axles.

    I would rather diagnose the problem and fix it, than just start replacing parts. It may come to that though!!

    It does not seem like it would be the wiring under the trailer based on the way it is installed.

    I did some OHM test this morning. Reading from the trailer connector, I get 1.4-1.5 ohms.

    Is this indicative of anything? From other sources I gather 4 brakes should be around .8 ohms.

    Does that sound right? Reading through all the wiring, connectors and splices could amount to 1.4OHMS???

    Thanks,

    Jerry

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