Troubleshooting Weak Trailer Brakes Where One Magnet Does not Activate

Updated 03/08/2016 | Published 03/07/2016

Question:

I have a 2015 Ford F350 diesel with the integrated trailer braking system. With my older 2003 36foot 5th wheel toybox it seems the trailer brakes are not engaging satisfactorily. At slow speed I could feel them tug but even with the gain set to +10, I didnt think I was getting the braking I should be getting. Its a heavy rig and hope Im not expecting too much. I am systematically troubleshooting both trailer brakes and the new truck. The trailer brakes shoes, adjustment, etc have never been serviced. I just checked the shoes and while they are ample in thickness, I see that they are cracked and showing age. On the first magnet I checked, it didnt seem to be charging so I started back at the truck connection and am working my way back. It could be bad wire connections on the trailer but want to start forward and work back. At the bed connection with integrated system set to 10, I am getting +/- 5.25 volts with the trucks brake pedal mashed and nearly =/- 13 volts with the manual controller completely squeezed. Is this normal? I just ordered all new assemblies 2-18100 and 2-18150 Hayes/AL-KO so the pad and magnet issues should be solved. So provided my voltage output is in the proper range I should be good to go....or stop as it may be. Thanks!

asked by: Al

Expert Reply:

Since you ordered new brake assemblies I would think that once you install those and properly set the brake tightness you would be good to go. If the one magnet wasn't getting any voltage to it then that would explain why that assembly wouldn't activate.

The voltage you tested for at the trailer connector would be normal if your controller was set for 5.25 volts as the max gain.

For proper initial trailer brake assembly setup check out the video (see link). Beginning at the 4:23 mark, our installer shows how to adjust your trailer brakes.

I also attached a help article on testing brake magnets for you to check out as well.

It is not too much to ask to have your trailer brakes be strong enough to lock up the tires when they are set to max gain either.

expert reply by: Jameson C