Help with trailer brakes

lenr wrote:
When measuring the resistance of electric trailer bakes at the trailer end plug, you should get 4 divided by the number of wheels. I got 1.0 – 1.1 on my two axle trailer. 28 is WAY too high for electric brakes. Although hydraulic over electric will be higher, I don’t have experience with them. My 2012 F-350 came with the brakes set to electric. You may have to have the trailer or a dummy plugged in to change the setting in the information panel—it doesn’t seem to come much alive without anything plugged in. I’ll bet the problem is with the trailer wiring. I’ve had the best success replacing ALL brake wiring—not trying to find where the problem is.

Thanks lenr. That sounds like what I would have suspected. I think the controller numerical setting is supposed to be the applied voltage, in my case around 6. So with 1 ohm resistance that would be a brake draw of 6 amps. My 28 ohm resistance would allow just a couple hundred milliamps. Not enough to work the brakes -- yet they work. I wonder if I have an intermittent bad connection where applied 6V can "burn-thru" corrosion or similar. I'm going to unwire the magnets and measure them directly. And if I just look for voltage drops across joint to joint it should be easy to locate the problem. If it's corrosion, I'll just replace it all. But I'm suspicious of a workmanship error. Trailers aren't built by master craftsmen.