Forum Discussion

jjbrown6818's avatar
jjbrown6818
Explorer
Apr 14, 2014

Brake Wiring?

I have encountered a problem with my 2009 Montana 5th wheel (GVWR 15500). Some background first. I have had some blowouts on both sides. I also replaced my umbilical cable (7 pin). I replaced the cable because the molded plug end at the truck had come loose and exposed the wired. I have a 2014 RAM 3500 with a 7 pin plug in the bed. The truck has an integrated trailer brake. I have an error that states that I need to check my trailer brake wiring. It is sometimes followed by a notice that the trailer is disconnected. The warnings disappear within seconds and checking the brake verifies that the brake is working as expected. I know this is a problem and new because just before getting this truck, I had the same problem with the truck I traded in (2012 Ram 3500). I thought that was a problem with the truck, but now that I have received the same warning with this new truck I suspect the trailer.

Now, what have I done so far? I checked the umbilical cable and the connections appear to be clean, neat, and tight. I haven't taken them apart but there is no apparent corrosion or misconnection. I visually checked the wires at the back of the wheels where the brake wires go into the wheel area. No chaffing or breaks or corrosion.

What is the next suggestion? I am on the road and don't have a clue of where the brake system wiring runs. All the trailer lights work correctly and don't go out except as
commanded. I have looked through all my paperwork but don't know where the wires run or how they work electrically. I have the integrated brake set to 4.0 for effective braking.
  • 2PM_s's avatar
    2PM_s
    Explorer
    Apr 15, 2014
    You are not going to believe this, but I had the same problem with a 2010 Ram 2500. To make a long story short, I stopped using a certain 2-way walkie talkie and I stopped getting the trailer disconnected on the read out. If, by chance you are using a 2-way you might check it out, otherwise keep looking. I did think I could relate the 2 together.
  • 07PSDCREW's avatar
    07PSDCREW
    Explorer
    Apr 15, 2014
    On second thought I see now that your TV is a 2014. Highly unlikely to be a problem....Sorry for my useless info
  • 07PSDCREW's avatar
    07PSDCREW
    Explorer
    Apr 15, 2014
    You mention that you have the bed plug for your fiver... I suggest checking the connection from the factory truck side connector to the bed plug extension/pigtail. I was having brake problems as well. I replaced the complete brake assemblies, all trailer wiring for the brake system and upgraded to 10ga wiring. I also replaced the umbilical... All with no success in fixing my brake issues. I also kept getting a "TBC FAULT" or "CHECK TRAILER" Message. After all that, I dug into the truck side wiring and was shocked when I found the harness plug full of green and corrosion. I had installed the in bed plug two years prior and all plugs related to this pigtail were corroded. It ruined my truck side harness connector too. I fixed it by splicing all wires directly and weatherproofing. All is well now. Hope this helps...

  • lenr's avatar
    lenr
    Explorer III
    Apr 15, 2014
    In my short experience open connections are more common than shorted wires on trailer brakes after a few years of weather exposure; however either may result in no brakes. Good brake controllers run a small amount of voltage through the circuit and check for proper current flow giving a warning if it’s not there. Instead of spending a lot of time checking through the whole circuit for problems, I suggest just running new wiring from the 7 wire umbilical junction box to the wheels with all new splices at the box and wheels. One 10 ga. brake wire is the minimum for 4 wheels. I prefer to use 2 12 gauge wires, one to each axle which results in less voltage drop (and more brake action) to the wheels. I run one to each axle so if I lose one, I at least have the other axle’s brakes. My son was having the problem of no/low brakes on his trailer. After running the new wires, he can’t believe how much he has to turn down his controller to keep the wheels from locking up.
  • khalsey's avatar
    khalsey
    Explorer
    Apr 14, 2014
    The wires going through the axles may have insulation worn and shorting out sometimes. I have had five 5th wheels that I purchased new and have learned that it doesn,t take a lot of miles to wear thru if there is a kink in wiring going through axle. I just pull them out and zip tie wires on outside of axle.
  • John_Bridge's avatar
    John_Bridge
    Explorer
    Apr 14, 2014
    Measure the volt reading where it comes into the trailer near the king pin box. (junction box). If you've got 12. something volts, fine. Then check each hot wire going to the brake drums. You will have to "nick" the wires and re-seal them with silicone. You should have near 12 volts at all the wheels. The process doesn't take all that long. You'll need someone to step on the brake peddle for you.
  • rrupert's avatar
    rrupert
    Explorer
    Apr 14, 2014
    You didn't mention checking the breakaway switch and wiring. Just a thought.
  • jjbrown6818's avatar
    jjbrown6818
    Explorer
    Apr 14, 2014
    I will check all the grounds and trace the wires back as best as I can. I can't attribute the warning to any bumps or shakes. I will be driving along and the warning will come on and disappear. It might give the warning several times for several minutes and then nothing for several miles or several hours. Thanks.
  • KCFDCapt's avatar
    KCFDCapt
    Explorer
    Apr 14, 2014
    I would check for a poor ground connection. The lights draw far fewer amps than the brakes do so will function with the poor ground. Locate the ground wire on the 5w, disconnect it, thoroughly clean the frame to bare metal, clean the connector, and then put it all back together.

    This is only a guess using the most common problem.

    Good luck with your troubleshooting.
  • waltbennett's avatar
    waltbennett
    Explorer
    Apr 14, 2014
    First off, have you gone here: http://montanaadministrator.forumco.com/ and become a member.

    Next, I'd say you've either got to have at least an ohm meter and a lot of time to trace things out or bite the bullet and take everything to a GOOD RV dealer - which will cost $$$$, but probably solve it all quicker.

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