Trailer break question.

[JohnCh]

I had my dealer install a factory trailer break today (2017 Ram 1500). When I connected to the trailer, the truck screen did not recognize the trailer so the break didn’t work. The trailer breaks show about 4.5 ohms at the connector to ground and I think that’s about right for the magnets. The truck output pin for the trailer breaks only shows 0.8 to 1 volt, it bounces back and forth, with the knobs squeezed together. It should show 12 volts, right? Any suggestions? Is there some trick to making the truck see the trailer so it sends the volts out? All of the lights work fine. Does anyone know if there is a dedicated fuse in the truck for the trailer break volts?

 

[crash68]

How many brakes are on this trailer, that sounds like the resistance for one brake. If you have four trailer brakes it should show about 1 ohm.

 

[JohnCh]

How many brakes are on this trailer, that sounds like the resistance for one brake. If you have four trailer brakes it should show about 1 ohm.

Two axles, but only one has breaks. So two breaks I guess. Even if one is open, without a trailer connected would the controller still put 12 volts out?

 

[crash68]

Did you test the brake output voltage with it plugged into the trailer? Without a load, the voltage may not read correctly.
The fuse is in the under the hood fuse block,
F11 for the ITBM
F30 for the +12V

 

[JohnCh]

Did you test the brake output voltage with it plugged into the trailer? Without a load, the voltage may not read correctly.
The fuse is in the under the hood fuse block,
F11 for the ITBM
F30 for the +12V

Thanks, I’ll check those. I just checked on the pins with no connection. Pins for the lights and such showed 12 Vic.

 

[JohnCh]

Finally have this sorted out. One of the brakes was missing the magnet. Replaced the brakes and all is working. Thanks for the help.