I pull a 50' wedge and have had an intermittent problem with the brakes. tekonsha controller has a rapid flash that they say is a direct short. rewired brakes from plug to brake backing plate and thought it was fixed. WRONG. could this be a problem with the magnets or something else inside the hub. How do you diagnose a brake short such as this?

 

I think the magnets have an ohm resistance when you put an ohm meter on them, not a 0 reading. The wire inside the brakes could be grounding out. You have to pull the drum to check for that.I've seen shorts in just about every place possible on electric brakes. Some can take some time to locate.

 

Start looking either for shorts or a lack of current draw when the brakes are applied.

Check them by a process of elimination - disconnect each brake and test.