Troubleshooting Brake Controller That Gets Hot and Trailer Brakes that Lock Up

Question

Question:

it always worked fine then we hooked up the horse trailer i calibrated tried to move lockup wait a second it would release so i felt the unit under the dash was hot so i unhooked undid the big round connector and noticed the white wire come undone im thinking it must of shorted out we had it installed by shop with the box getting like it did to hot to ttouch

asked by: Clyde

0

Expert Reply:

It does sound like there is a short on your trailer. If the brakes locked up and the brake controller unit got very warm it sounds like there is a short on the trailer's 12V power circuit that is causing the electric brakes to lock up. It is possible for different circuits to become bridged together and your 12V power feed might be getting to the brakes.

First, check the trailer plug inside and out for signs of corrosion. Even slight greenish or whitish discoloration can indicate corrosion. You can try a spray-on contact cleaner like Caig De-Oxit to remove any corrosion on the connector. You can also test the trailer wiring by itself by disconnecting the trailer plug from the truck. Apply 12V power from the truck battery (or from a spare) to each circuit on the trailer, one at a time, to make sure everyone functions. If not, trace the wiring for each circuit and look for cracked or worn insulation, especially around points where the wire has to bend and where it touches the trailer frame.

If the brakes engage and release properly when you apply power in this way, then the issue may be in the controller. You can apply a circuit tester like # PTW2993 to the controller's blue output wire to test its function. Cut the blue wire a few inches from the controller (so you have room to re-connect it) and test the end from the controller while you press the manual override. If you detect a signal, then the controller is okay; if not then it may have been damaged from the short-circuit and needs to be replaced with a unit like the Prodigy P2 # 90885.

expert reply by: Adam R

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Answer 1

How old is the brake controller? Does it still seem to be working properly? Overheating brake controllers aren't common but it would most likely indicate a short. I can help you troubleshoot the controller though. Testing the brake controller…

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Answer 2

I have a suspicion about what might be causing the problem you mention. Do your trucks have 6-way trailer connectors? Or, do the trucks have 7-way connectors, but you are using a 6-way to 7-way adapters because the trailers use 6-way connectors?…

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Answer 3

You can use a circuit tester like #PTW2993 to test the 12-volt circuit on the 7-Way to see if it is has power. If it is not and the 7-Way is factory it might just be a blown fuse to that circuit. Use the owner's manual to find the location of the…

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Answer 4

Since you have checked out your trailer's hydraulic lines and confirmed the brakes are in good shape, the cause for the heat in your one drum could come from something else. If only one of your drums gets hot when you tow it could be that…

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Answer 5

The only wires that could be hot all the time on a trailer connector is the 12-volt hot lead, which is usually a black wire, and, if applicable, the auxiliary power wire, which is normally yellow or purple. The blue wire is usually for electric…

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Answer 6

I would recommend completely ruling out the bearings by closely examining them and the spindle for discoloration caused by overheating. If you have determined that it is the brakes that are hot, and not the hub itself, I would recommend readjusting…

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Answer 7

Trailer breakaway batteries are usually rated for 5-amp-hours and are designed to keep your four brake assemblies engaged for 15-minutes in the event of an accidental disconnect. The only way the breakaway battery could heat up your drums is if it…

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Answer 8

Excessive rust would definitely weaken the pull of the magnet, so I would recommended replacing the magnets on your trailer if they are severely corroded. If you have power going into the magnet and it is not engaging at all, this again would be an…

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Answer 9

The Reese Friction Sway Control #83660 like what you referenced can be used either on the right or left side of a trailer. To switch sides you will need to remove the slide bar and then reinstall it upside down. For trailers 26 feet long or more, it…

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Answer 10

Hubs will heat up when driving, but if it feels like they are getting too hot, then you will want to look at a few things on your hub. My guess is that the spindle nut is too tight and the added stress on the bearings is overheating the bearings and…

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Answer 11

Yes that is correct, the bow will always face forward on electric drum brakes. The magnet will be on the bottom and the arm that the magnet is attached to will bow towards the front. Also the shorter brake pad will always be in the front of the…

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Answer 12

The first thing to check is the connectors to make sure there is no corrosion present. That can cause a variety of problems. If that checks out you will need to do some other testing. You can sever the blue wire about 4 to 6 inches from the back of…

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