Elect Brake Problem

I found where one of the neutral wires and the bright blue electric brake wire had been rubbed bare going thru a hole in the aluminum frame.

Bingo! :B

if they work with the bar it is not in the wiring, period. Low brake amps with the pedal could be weak pucks. My Genesis will not put much on the readout when not moving due to the inertia device. I tow in the mtns mostly and see all different readings depending on grade and how much pedal pressure.

I found where one of the neutral wires and the bright blue electric brake wire had been rubbed bare going thru a hole in the aluminum frame. Not really bad but enough to show an ach spot. I Was checking voltage at both ends and kept getting a different reading. Pulled the plastic under belly material and found the problem.

It is funny now that I repaired the wires the one wheel does not work by the pedal unless moving any more. Boy, do I love electric brakes!

Thanks for the advice.

When I have trailer on jacks, the drivers side rear brakes works by just spinning the tire, the rest do not work unless the bar on the controller is pushed. Haven also tried pulling and only that one brake is working. Checked power coming out of truck connection for the electric brakes and it barley will light bulb in circuit tester. Even tried another controller, same thing.

If you have electric brakes, pumping the brake pedal does nothing except energize the magnet and make it stick to the inside of the drum...turn the adjuster until the wheel locks (can't turn it by hand), that centers the shoes, then backed the adjuster off until the brakes drag slightly (count the number of clicks you move the adjuster), then adjust the others the same way.

bkick wrote:

...
Did the same adjustment to the front axle, does not work using brake pedal. Had wife push bar on controller and all brakes locked up.
...

With inertial controllers, pushing the brake pedal will have no effect if you are not moving.

Even with my Ford's built-in controller, there will be little voltage applied to the trailer brakes by the pedal when not moving.

The only sure way to activate the trailer brakes when not moving is by pushing the bar on the controller or pulling the plug on the run-away switch.

EDIT: oops, I see RoyKen has already said this.

I have to rotate my trailer wheel an half turn when jacked up to activate the electric brake magnet PADS on my trailer.

Some brake magnets produce a tone when activated. Some folks will hold their camping compass up close to the wheel and it will deflect when brakes are activated.

If you have a clamp on Sears AMPMETER you should read 3amps DC CURRENT on each brake lead when electric brakes are applied.

Also my newer 2010 F150 Truck that has built-in OEM brake controller will not send braking voltage to the trailer using the brake pedal unless the truck is moving down the road at least 10MPH. The slider manual switch is only way to lock up my electric brakes when sitting still.

Roy Ken

Moved to Tech Issues forum from DIY.

While pulling trailer to park in front of the garage to check wheel bearings as I stopped to back up I noticed the drivers side rear tire locked up when I stopped. Jacked trailer up, pulled all four tires and hubs. Found passenger side rear seal had leaked and brakes coated in grease. Replaced both rear brakes and magnets. Hooked truck to trailer, set the controller (10 month old Primus IQ) Started adjusting the brakes on the drivers side rear. Had wife pump the brakes to help set them as I adjusted. Worked great, went to the other rear wheel, did same adjustment. Brake did not work, ok, maybe broken wire inside axle, ran jumper from working wheel to opposite side, nothing again. Checked current with a circuit tester, light is dim on non-working side. Did the same adjustment to the front axle, does not work using brake pedal. Had wife push bar on controller and all brakes locked up. Am going t0 try checking entire wiring from controller to brakes today.
All help will be put to good use.

Bkick

Which brake controller are you using?

Voltage output via brake pedal is varied based on how hard you brake.
Voltage output via manual lever allows full voltage

Corrosion, bad connections, wiring scheme, magnet condition, brake adjustment all affect how/what works when controller output voltage is applied (varied/full voltage).

Need to check voltage at truck 7 pin receptacle and then at each brake connection to pin point where your issue is.

Also when was the last time you adjusted the brakes of trailer?

And how did you find that only one brake was working when pushing truck brake pedal......explain your testing :H