Trailer Brakes - Open then short?

[BroncoMarc]

I've got a car trailer with brakes on one of the axles that is about 2 years old. I'm using a Tekonsha Prodigy brake controller on it. 50% of the time it tells me I'm connected. Every once in awhile it will start flashing nc (No Connection). Sometimes it flashes sh (Short). If I hit the brakes when it says sh, it then says ov (Overload)



I've tried changing out the trailer connector and re-crimping all the wire connectors where they go into the back of the wheels. This didn't change anything.



A friend of mine says that the magnets can go bad and cause opens and shorts. Is this a logical thing to change next?

 

[AggieJustin]

If it only does it with this trailer, and you've checked the wiring from the plug to the brakes for bad spots, then the magnets are the next logical choice.



I would double check the wiring from the front to the back to make sure you don't have any bad spots in the insulation. Just a little bit of water or other crud in there can cause you to short to ground or lose your connection.

 

[Slow Six]

I had a similar problem on one of my trailers last year. After a couple hours of trouble shooting I found the problem. The brake wires ran from one side of the axle to the other end through the axle tube. There was a very small wear spot on the insulation of the wire. Depending on how the wire laid in the tube from movement on the road, I was getting codes from the controller. It was a real bear to find this one, and when the problem is intermittent, it can be frustrating. I found my problem by using a voltmeter and isolating one axle at a time and then one wheel at a time. I find the fault code feature of the Prodigy to be good help. Be patient and hang in there, you'll find the gremlin.

 

[jelag]

I have several trailers with electric brakes..... Their really bad for falling apart on the backing plate and dropping small parts into the drum... . I'm guessing you've got something loose inside one of the drums... . sometimes it shorts the wires to ground... sometimes it goes open... ...



One of our trailers had the wire cross from one side to the other side inside the axle... that wire would rub on the bottom of the axle and wore through the insulation and sometimes those brakes would work and other times they wouldn't..... we finally took the complete set apart and rewired the trailer, making sure that our work was better than the factory that put the trailer together... .



Hope this has helped... .



Jim

 

[CPG]

Thats what is nice about the Prodigy, it lets you know somethings wrong.



Chuck

 

[ropinfool2]

I think jelag and slow six hit the nail on the head. The first thing I would do is replace the wiring in the axle tubes. Obviously it will be hard to put new wire inside, I just wiretie it on the back side of the axle. Then pull the old wire out. You'll be suprised at how much bare wire is in there. Learned this the hard way. Good luck. John

 

[K5IP]

When this happpened to me it turned out to be a brake magnet wire inside the drum. It came out of the small clip which was supposed to retain it and the rotating wheel finally wore through the insulation. It was obvious, and easy to find once the drum was removed.

In my case I new it was in the wheel because short would come and go with each revolution of the wheel.

Rog

 

[mike r]

K5IP, mine did the same thing. Take the drums off and see if the wires are hanging loose and worn through. Use some insulation off an old rubber extension cord or small tubing to reinforce the insulation before you refasten it. I've had a few of those no-connection instant-connection heart stoppers.