Trailer Brakes Not Staying On

That is good news; your shop found a surprise inside. Having all four wheels checked and serviced is a really good thing to do. It rules out a lot of possibilities. Now you have a benchmark point; tracking towing mileage in the future helps determine how many miles have gone by since the last brake and bearing maintenance.

If the issue persists, the axle tube wire issue may or may not be there. You said a 2015 camper when new and over 20K miles. 7 to 8 years of time and 20K plus miles most likely have started some wear on the insulation in the axle tube. How much depends on how bumpy the roads were during that time which is an unknown. This can be part of your next steps plan if the problem persists.

These kinds of problems are a true process of elimination.

Let us know how it ends up by the time your trip is over.

John

First of all, thanks for all the advice and help. It has been SO helpful! In the end, after replacing the controller, checking the connections, wires, and grounds, I felt there wasn’t much more I could do from the road, so while here in Bend, OR I was able to get a repair shop to look at the hubs. They said the magnets on one side were shorting out, so… hopefully this is really the problem. They are doing a brake job on both sides (plus bearings and some other misc parts it may or may not need), and hopefully this will resolve everything and get us back on the road. We head north tomorrow so my fingers are crossed that this problem is over. Thanks again!

msmith1.wa wrote:
Also don't go replacing parts until they are diagnosed to be bad.

Do you know someone that would let you connect your trailer to their truck to try to isolate if the issue is the truck or the trailer.

Good advice! Replacing parts before checking all of the "free" stuff and using some basic logic to troubleshoot is a sure way to frustrate you and relieve you of any extra cash you might have. My first move would also be to either hook your truck to another trailer, or your trailer to another truck. Any work or parts replaced before determining whether you have a truck problem or a trailer problem is time and money wasted.

Since you changed the controller, you may have a real short.

Possible places that may create an actual short in the brake power line.

In the truck:

Check all wires from the controller to the 7-wire receptacle on the back of the truck. Blue is a color often used for the brake hot wire; confirm that it is your color in the harness and trace the harness from the controller to the actual pin in the 7-wire receptacle. If the insulation is skinned, it can touch the frame, which is a short to the controller.

On the trailer:

Is your 7-wire plug an add-on plug to the end of the cable, or is it all one molded cable and plug? If it is an add-on plug, it can be possible a strand of wire in the plug can touch another terminal from a bad wiring job. You can take them apart and check. If it is an all-molded cable and plug, this issue does not normally happen.

I'm not sure about your camper, but most newer campers have a junction box where the 7-wire cable enters and splits into camper DOT lights and the camper brake wiring. They have to connect to the camper blue brake wire in the 7-wire cable; that splice may have a problem.

Trace the camper blue brake wire out of the box all the way to the axle area, and look for skinned insulation.

Inside the brake itself (you must pull the drum to see inside), the magnet coil leads have small clips holding the wire to the magnet arm. Those clips have creaked or were not right from day 1, and the magnet wire gets skinned and can short to the ground. I have seen this; it is not common, but it does happen.

The coil comes loose from the magnet arm due to the clip breaking and gets ground up sideways over time. If the coil wires are exposed, that can be short. When this happens, the magnet is shot, and the magnet arm can also be bad. I have seen this too.

Then there is the worn insulation on the hot wire inside the axle tube. This is a classic failure mode. This is hard to test unless the hot wire touches the tube just right to find on an ohm check. And the only way to test the wire is to unhook the coils so you can test only the wire and hope it is touching so you can find it. When I find this problem or suspect it, I give up using the wire in the axle tube and run new wires outside it. Then you can pull the wire out of the tube and see the skinned insulation exposing it or close to it. There are a few ways to run the wire, but if you attach it to the tube, pick the back side so that the wire does not get beat up if you run over weeds or brush by accident. You can also run the wire attached to the bottom of the camper to cross over.

You are in the process of elimination at this point. All the checks above, except pulling the drums and the wire in the tube, are not that hard to do. Not sure if you are equipped to pull the drums; a sticky at the top of the towing forum will help show what you will be up against and how to do annual brake and bearing service.

Whenever I do a trailer brake or bearing maintenance pulling the brake drum, the odds are favorable that you might find a surprise inside. Nothing shocks me anymore about what one can find wrong inside; these brakes are not robust like the older auto drum brakes.

And while you have the camper up on jack stands of the block with the wheels off, assuming your camper has leaf springs, check the suspension; the nylon bushings that come standard in the spring eyes on many campers can be worn through between 8,000 to 10,000 miles on some or all of them. The equalizer center pin wears the fastest as the movement is more. When that bushing goes out, it starts wearing the casting; the whole equalizer starts to wobble and accelerates the shackle plates and pins wearing from spinning as the serrations on the heads of the pins are worn out. Another classic trailer failure is broken shackle plates from excess wear on the pins; once they start spinning due to the serrations being worn off that started from the wobbling equalizer, they start elongating a slot in the shackle plate which, in time, cracks the end of the plate off. Then the spring flies up into the fender well, leaving you stranded.

Hope this helps, and let us know how it goes.

John

So, I have replaced the brake controller. For 5 hours of our trip today the brakes worked well and the brake controller was working properly… Then… the last hour of the trip today the controller flashed a code telling us that it thought the trailer brakes had a short… Ugh. I thought we had it with the new controller, and that was the longest the brakes have worked in a while… but I guess I still haven’t got this one figured out.

I am going to suggest you dig a little deeper into the plugs and actually take them apart and look at the inside for corrosion also.

I had a brake issue that presented the same as you described. All of the terminals on the trailer end looked fine externally, but inside the brake terminal was corroded to the point that it was two pieces that would sometimes make contact but mostly not.

Also don't go replacing parts until they are diagnosed to be bad.

Do you know someone that would let you connect your trailer to their truck to try to isolate if the issue is the truck or the trailer.

Hi,

Your added info has helped.

You are correct, the brake controller was an aftermarket add on by someone. Ford never started adding brake controllers until the 2005 Super Dutys with an integrated controller. The last Excursion, a 2005 model, never got the upgrade, nor did the V10 engine upgrades the Superdutys did.

I agree with Barney, you "might" now have a brake controller issue. At this point, ideally, you can sort out, is the problem in the trailer or the truck?

Here is one way to help sort out truck or camper. You stated this,

-We hooked up and initially the controller had a stead green light indicating everything was fine.
-Before moving the trailer the contrôler began blinking a single green light noting a short or excessive current request.

That is the setup for the test if you can recreate it or close to it. The truck and camper hitched but not moving, and the brake controller started acting up.

By hitching up and powering the brake controller, but not moving the trailer, the brake controller can warm up, and if the controller starts showing faults, then try this.

Step 1, Unplug the 7 wire cable from the truck. Position the 7 wire cord up so it will not drag the ground.

Now, with the 7 wire disconnected, pull the emergency break away, this will apply full power to the brakes.

Move the truck ahead very slowly. You are trying to do a drag test. You should feel large braking action on the trailer, you do not want to drag the wheels, but should feel very hard braking. Gravel is best for this test so the tires skid, but you can tell real quick if the trailer is braking hard on a hard surface road, 1 or 2 feet movement will tell you, but the camper does have to move about 6" rolling forward to engage the brakes. The wheels may or may not lock up, but you should feel the brakes working.

If the camper has brakes, this does not mean 100% that there is not a trailer problem, but it rules out many things. Enough to at least suspect the issue is in the truck.

When you unplug the 7 wire, and the truck was on, the controller may stop the fault or not. It should sense an unhooked trailer at least. Not sure what it will read out as, as the controller may be damaged. But you at least now know, the trailer brakes worked during the breakaway test.

There is also something you should know, some brake controllers cannot handle a large current back feed from the camper. By pulling the emergency break away, with the 7 wire cord attached to the truck with the brake controller powered up, is a high back feed current into the controller from the camper battery. That back feed action has damaged some brands/models of brake controllers.

If you want to try to reset the brake controller in a test mode, pull out the 7 wire cable and plug it back in, or turn the truck power on an off, but do not use the emergency breakaway switch as that can be a problem.

Here is a thought, when your breakaway switch was failing originally and melted the switch, that event was sending a back feed of current into the truck brake controller. That may have damaged the controller, and now you are fighting a brake controller issue.

There should be nothing wrong with your new breakaway switch unless something really odd going on. It is just a simple switch, on or off, unless it is corroded which is not yet.

Hope this helps, and let us know how it goes.

John

I would try replacing the brake controller. Don't know about the policy now but a few years ago Tekonsha would replace their brake controllers for no cost. All you needed to do was take to a place that sold them and they would give you a new one. Worth a try now I would think.
Barney

For a bit more information…
My brake contrôler is a Tenonsha Sentinel. Our tow vehicle is a 2003 Ford Excursion and I’m assuming the brake contrôler was purchased and installed early in the life of this vehicle by the original owner.

Our trailer is a 2015 Rockwood Signature Ultralite by Forest River model # 8327SS. My brother bought it new. It has more than 20k towing miles on it.

For this controller… generally when you hook up the trailer cord there is a steady green light that is illuminated letting you know everything is working correctly. If that green light flashes it indicates a direct short or an excessive current request. If brakes are applied when the green light is flashing, the additional lights (meant to indicate firmer trailer breaking) all flash and you feel no trailer braking so you know that the brakes are not working.

On my drive yesterday…
-We hooked up and initially the controller had a stead green light indicating everything was fine.
-Before moving the trailer the contrôler began blinking a single green light noting a short or excessive current request.
- I crawled under the trailer to once again check the grounds and the see if there could be a visible problem, I checked the connections to the batteries, and I took a screw driver and moved all the contacts closer. I plugged in a 7 pin tester and it showed no problems. Green light was still blinking. I pulled the break-away plastic pin and reinserted it and the green light on the contrôler went to steady green.
-As we began driving… Initially the steady green light was on for 30 minutes, then the light flashed indicating a short etc., then the light went steady green again for an hour, then the flashing started and stayed on for more than an hour when I pulled over and unplugged the break-away plastic pin and re-inserted it. this brought the steady green light back on for a while then the controller really did some weird stuff… went completely dark for 30 seconds, came back on with a steady green light, then flashed and did this cycle at random times. Last 30 minutes of the pull yesterday was a flashing green light again indicating no trailer brakes functioning (and it felt this way too).

Could the previous problem with the break-away switch (that I have replaced) have damaged the controller? Should I look at replacing that? Could I maybe have gotten a faulty new break-away switch and think about replacing that? We have towed this trailer from coast to coast with no braking problems until these past few days.

eHoefler wrote:
Check your umbilical cord to the vehicle, and the connections in the junction box on the the trailer. You have a poor/loose connection some where.

DITTO.

It's probably a loose umbilical cord at the truck receptacle.

On the trailer cor, take a screwdriver and move the electrical contact to cause more "spring" tension when the cord is plugged in to the truck.
Also check the truck and trailer connector for dirt, grit, grime, corrosion.

And NEVER use one these caps to "protect" the trailer plug. They cause more problems than they solve. This video I made proves it.