The brake controller always announces when I plug in the trailer. Then when I apply the brake or use the manual control, it displays a bar that shows more dots as the pressure increases. Right now, it's not doing nuttin'.
Ohms law V=IR or R=V/I says that if each axle draws 6 amps, the resistance would be 12/6 = 4 ohms. Three axles in parallel would read 1/R = 1/4 + 1/4 + 1/4 or 1/R = 3/4 or R=4/3 = 1.33 ohms and I'm getting 3.3 ohms. Even if one of the axles is disconnected (it's happened before), that wouldn't explain why the controller isn't doing anything.
I think the reading I got is in the ballpark. Open or shorted would indicate a wiring problem in the trailer. I think my problem is in the truck.
There's nothing mechanically wrong with the brakes. I adjusted them just before leaving on this trip.
