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TravelingWilbur's avatar
Jun 25, 2025

Electric brakeissue

I have a 2005 5 Springdale 28' travel trailer that i recently installed new backing plates on all 4 wheels. when i tried the controller manually nothing happened so i just ended up using truck brakes. however when i left the campground one wheel on the drivers side was locked up. any suggestions of what might cause this? The drums were in good shape so i used them as they were.

6 Replies

  • The only reason I didn't mention the breakaway pin is mine looks like it will possibly break or removal and not go back in. So I basically leave it alone and find other ways to test.

    To the OP, if you do decide to pull the breakaway pin make sure the umbilical is not connected to the tow vehicle. We've heard reports in the past of the backfeed from the brakes frying some brake controllers. It may be an urban legend. But for the effort to unplug is it even worth the risk?

  • Thanks for the more information. Many of the newer trucks have independent fuses for trailer towing. I would definitely look at the fuses before removing the plug.

    As far as replacing the plug that's a good idea if the original looks damaged or corroded. But I would first remove just the brake wire and the trailers battery charge wire from the plug. Then use an extra 15 amp fuse and connect the fuse between the two wires to apply the trailer brakes. Does the fuse immediately blow or do the brakes apply or does nothing happen?  It's a quick test that will tell you if you have a wiring short or if the power is even getting to the brakes. 

    If you have a compass you can have a helper apply the manual override on the brake controller while you hold the compass near each wheel. If the brake magnets are energized the compass needle should swing to point at that wheel. 

     

    • StirCrazy's avatar
      StirCrazy
      Moderator

      why wouldn't you just pull the breakaway pin? that will tell you the same thing, the only thing it doesn't test is the pig tail, and it lets you measure the amperage at each tire with a clamp on dc amp meter so you can tell if each magnet is working.  

      the way to do it first is just use a Ohm meter and measure from the plugin from the ground to the brake pin, if you have 4 brakes then for most setups if everything is good you should get just under 1 Ohm like 0.8 Ohms.  this will confirm all your magnets, grounds and the rest of the wirings is good. 

      if your like me when I was checking it yesterday and got 1.2 Ohm  then you pull the breakaway and move on to each individual brake.   

  • Thank you for your response! i ordered complete kits for 2 axels from amazon. The drums that i received turned out to be the wrong bolt pattern so i used the existing drums as they measured the same as  the new ones. replaced the backing plates that had all new components(magnets and brake pads). made sure that the small pad was facing front. we adjusted them so there was just a little drag but turned freely. when i started towing i tried the manual function on the controller and it didn't slow down at all. Making me believe that they were not tight enough. I just used my truck brakes to stop thinking i would adjust when i got back. however when i went to leave the campground 1  wheel was locked. i freed it us enough  to get home but could smell brakes when i got home.

    Wiring was done just as it was and i did not get any errors from the controller. i have ordered a new plug for the 7 pin and will be replacing that today in case the signal was not getting to the brakes due to oxidization of the plug.

    • StirCrazy's avatar
      StirCrazy
      Moderator

      did they not have the labels on them stating left and right, they should have?

      did you put the little clip on after the magnet , or if it was preassembled did it have the retaining clip installed?  

  • we would need a bit more information to hazard a guess. Explain the what exactly yu replaced and what the system consists of.

    1. Are the brakes auto adjusting or manually adjusted?
    2. When the drivers side wheel was locked up how did you get it unlocked?
    3. If you disconnect the battery and unplug the umbilical do all the wheels roll freely?

    My guesses are 

    You pinched one or many wires when you replaced the backing plates. Test by disconnecting the umbilical and disconnecting the battery on the trailer. 

    If disconnecting all power does not free the locked up wheel that brake is adjusted far too tight.

    If they are auto adjusting brakes. Make sure the backing plates are on the correct side of the vehicle. If on the wrong side then when in motion the brakes will adjust tighter with every application of the brakes.

    It's possible your tow vehicle has a blown towing fuse or problem with the trailer connection.

    It's possible the trailer umbilical is damaged. 

     

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