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Carlotta14's avatar
Carlotta14
Explorer
Nov 21, 2022

Trailer brakes not working

Hey , I installed a pair of elec brakes on my old trailer, left and right ! . After instal, when jacked still, testing, brake controller in truck stopped wheel from turning, but not foot pedal. No codes, 2016 sierra HD. when on the road, no diff. Chnged the 30 amp fuse. The dash says the gain is rising when pushing the pedal, but the wheels don't seem to be slowing ( I can usually feel when they are active) . When I hooked the wires up, i left about 4 inches of the old brake wire and hooked to that, should I have removed this section ? There was not a lot of wiggle room in the wheel well ! Thanks for any hep. M
  • Carlotta14 wrote:
    Hey , I installed a pair of elec brakes on my old trailer, left and right ! . After instal, when jacked still, testing, brake controller in truck stopped wheel from turning, but not foot pedal. No codes, 2016 sierra HD. when on the road, no diff. Chnged the 30 amp fuse. The dash says the gain is rising when pushing the pedal, but the wheels don't seem to be slowing ( I can usually feel when they are active) . When I hooked the wires up, i left about 4 inches of the old brake wire and hooked to that, should I have removed this section ? There was not a lot of wiggle room in the wheel well ! Thanks for any hep. M


    The way you are testing the system may be part of the problem. If the camper is off the ground, you spin the wheel, press the manual button on the brake controller and the wheels stop, OK that at least tells you the brake coils are getting some power. But it does not take much power to stop a wheel off the ground.

    When you are towing the camper, say at 20 mph down a empty road, if you press only the manual button hard, does it slow the camper at all? There are no truck brakes in this test, you are testing the mechanics of the brakes and the wire from the controller. If you do not get some braking feel in this test, then there can be a mechanical issue or a wire issue not able to deliver enough current. Did you adjust the brakes and if so, what was the feel you where after in adjusting them?

    Did you burnish in the brakes yet? You may not have, but it will need to be done before good braking will happen.

    You need to sort out, is the trailer brakes correct, and then add in the truck brake pedal test.

    You can also do a drag test. Unhook the 7 wire cable from the truck so you do not back feed the brake controller with camper electric. Pull the emergency breakaway switch, drive real slow forward, you should have brake lock up or a really hard drag. If this does not work, you have to back into why? This then points to the trailer has an issue. This test also assumes the break away switch is working. When the switches get old, they have been know to not work, corrosion in the switch stops current from passing and creates a lot of heat in the switch. Point, if the drag test does not work, make sure the breakaway switch is passing 12 amps if you have 4 wheels braking.

    Hope this helps

    John
  • The OP said "...when on the road, no diff." ,so I presume that a road test was already tried.
    Inertia based controllers need movement to operate properly, timed based controller do not need movement.
  • Control needs to feel inertia of vehicle slowing down to work. Manual lever works anytime. take it for a road test to check for normal operation.
  • What is the make and model of the controller?
    Sounds like a Proportional controller that is not calibrated.
  • joelc's avatar
    joelc
    Explorer III
    Jack up your trailer, have someone spin the wheels and then apply the break. It should stop the wheel. If this does not work you have a wired problem.
  • ^2112 is correct.

    Yes, best way to test, is to tow it. Most trucks with IBC will give a starting point for gain set. Mine states 6 of 10, for starting point. Now drive on pavement, where you can safely slide manual control lever full on, at say 25 mph. Most controllers, set properly, will just keep from locking the trailer brakes, and sliding the tires.

    Jerry
  • 2112's avatar
    2112
    Explorer II
    The controller only applies power to the brakes by pressing the brake pedal when the truck is moving. The manual slide always applies power when used.

    The reason being is you don't want/need current flowing through your trailer brake coils while sitting at a long red light with your foot on the brake.

    Tow it around the block to verify the controller is working properly when pressing the brake pedal.

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