I had a SH on my prodigy indicating a short. I pulled over at a gas station and found that its on one of my trailer tire brakes. I cut the power wire to that tire to clear the code and continued on. I am now at my hotel for the night and continued my investigation. I took the drum apart and saw no physical problems. I put a ohm meter to the wire and i am seeing 3ohms on the power wire and .5 ohms on the neg wire. Both were to chassis ground. I am thinking the magnet is bad, but i have never heard of a magnet go bad. Anyone have any suggestions what could be wrong or something else i could check?

 

If you disconnect both wires to the magnet, I would expect 3-4 ohms between the two wires, and no continuity between either wire and the housing of the magnet...

 

If the brakes have lots of miles on them, try this:
where the wires go into the magnets, carefully bend them back and look for splits in the insulation. I had that happen once - took me forever to figure it out. While the magnets were at rest, no problem, but once they rotated rearward while attracted to face of the of the drum the wires would touch the metal and the magnet would drop out.
Dry Creek

 

Magnets do go out. there have been many times I have replaced just the magnet. I will jack up the trailer and wire brake straight to a 12v battery. YOu should be able to here the magnet and ofcourse the wheel sould not turn.

what happens a lot of times is that the stator on the hub is worn unevenly and the new magnets are not making contact with the entire surface of the stator. If the new magnet is only touching 40% of the stator surface....thus you have only 40% of your braking power.

Been there done, done that, got the t-shirt.