Warning Hot Brakes?

I finally figured out the brake problem this weekend. Before we pulled out for the weekend Friday I took the time to test each magnet for ohms, amps and ground. One magnet was about .10 amps lower that the others. I pulled this one out of the circuit but that didn't help. I changed my controller and that didn't help. So I clipped the power wire on each magnet until on the last magnet the brakes quit failing. Not the proper way to test but it worked.

ScottG ,

I endorse your comment... personal experience with side to
to side"gremlin" in the axle tube , hidden in a bird's nest of electrical
tape and wiring...grounding out intermittently then completely...on the
L.A. Freeway system.... white knuckled for about 15 miles (the one
time I was thankful for freeway bumper-to-bumper !).

Thankfully, the technician at the RV service center had seen it before ...
many times ...quick fix, on my way.
Good recommendation !

The L.A. Citizenry were very understanding... many waved and saluted
as they blew by and around...

Charles

Pull the wheels on the trailer, check all the wiring in the hubs around the magnets, and then trace the condition all the way back to the pin box.

I would suspect that new trailer before I would the truck. I bought a brand new Montana and fought alarms on my Ford Integrated Controller all the way to Montana and back, and for another 6 months after. It came and went, but what an annoyance. I spent every free moment trying to blame the truck. It took the Montana Dealer about 6 seconds to figure it out while in for cabinet work on warranty. He asked if I was having any trouble with brakes as he was swinging a magnet with cut wires inside the hub.

Next time, I get my jack out and pull the wheels. I was just lazy and was looking for anything else that might be wrong.

jeepman71 wrote:
I checked the amps at the plug when applying the brakes with the lever I am getting about 7.8 to 8 volts and about 5 to 5.5 amps. I had the plug unhooked and went from post on truck side to socket on trailer side. Using the manual lever I am reading 7.8 volts on the controller and about 4 amps. It is a two axle with 7 inch brakes.

It appears you may have a broken wire to one of the axels that is shorting at times.

I checked the amps at the plug when applying the brakes with the lever I am getting about 7.8 to 8 volts and about 5 to 5.5 amps. I had the plug unhooked and went from post on truck side to socket on trailer side. Using the manual lever I am reading 7.8 volts on the controller and about 4 amps. It is a two axle with 7 inch brakes.

The P3 will give you the current draw. Most brake magnets have about 4 ohms of resistance. Thus a two axle trailer will have a resistance of about 1 ohm. Check the current draw when you apply the brakes with the manual lever. Compare this to the voltage applied. You should get about 1 amp per volt applied. From what you have told us I am almost sure you have a short or possibly a bad brake magnet. A Brake Smart controller or any other controller will not correct your problem. You have a wiring or trailer brake problem.

I'm back again. It was definitely an "Overload" message on my brakes. I have not had much luck finding a short in the wiring so I am back to give a little more information.

As was noted earlier I do have an exhaust brake so I don't rely on the truck and trailer brakes on descents. I have noticed that this problem gets worse or happens more with the amount of braking I do. If I have the P3 set on Power Boost 2 the warning will come on almost immediatley. If it is set on Power Boost 1 or off the power level has too come up to about 3 volts before the warning will happen. The more I am using the brakes as in stop and go traffic the more it will give the warning. I can definitely feel the trailer brakes ingage and then when the warning comes on I can feel the trailer brakes do away. It seems this is somehow related to a "heat" issue due to the fact that it happens with more brake pressure applied by the P3 or usage issue due to driving conditions this does not seem like a short in the wiring.Is this possibly a magnet problem? Is there a method to test the magnets with the trailer unhooked without the brake controller? If not what methods should I use to test the magnets?

Sorry for the lengthy questions. I am new to trailer brakes.

I got the same warning on mine back in June. The trailer had been setting since Mar. It gave me an overload warning while doing a pull test when getting ready to pull out for a trip. All I did was clean the truck & trailer plug with some brake clean and all has been good since.
Always check the easy stuff first not saying that is whats wrong with yours its easy.

ScottG wrote:
"Overload" is a completely different scenario. :S
It means there's a short in the trailers brake wire. The most common cause is the wire that passes from one side of the trailer to the other inside the axle tube has rubbed through its insulation.
You need to remove the wire from the axle tube and run it on the outside after repairing the damaged insulation.

Correct. Plus the brake system is not functioning on the trailer at all in this condition due the wiring scheme OEM builders utilize.

"Overload" is a completely different scenario. :S
It means there's a short in the trailers brake wire. The most common cause is the wire that passes from one side of the trailer to the other inside the axle tube has rubbed through its insulation.
You need to remove the wire from the axle tube and run it on the outside after repairing the damaged insulation.