Originally Posted by BBBlue
I am pulling a 14.5K 5th wheel trailer with my 2013 Ram 3500 dually. During the process of setting the trailer electric brake controller, I had to put 10% gain before I had the ability to slow the unit down from 20 mph with the manual slider on the controller. I had the controller set at Heavy Electric.
I conducted a test, which I am not sure if it was the correct way to check the output from the controller.
With the trailer cable hooked up to the 7 pin connection in the bed, truck running, I took a voltage reading at the brake pin located at the 7 pin connector on the bumper and got the following:
Controller set at 5% gain- 50% brake-1.9 vdc, 100% brake-6.38 vdc.
At 10% gain- 50% brake-6.3 vdc, 100% brake-7.46 vdc.
In addition to the above voltage checks, I also checked amps at each wheel magnet with the following results:
Controller set at 10% gain- amperage at each wheel was- 1.75, 1.78, 1.77, 1.76. Dexter manual specifies 3 amps
Is this the correct way to check controller output? If so, are the output voltages in the ballpark? Does the speed of the truck affect output from the controller when braking is applied? Any assistance would be appreciated.
With a standard multimeter you likely won't see full 12.5v because of the pulse width modulation.
The 2015 ITBM used an accelerometer to adjust Pulse width modulation. I believe there will be a stronger signal when the accelerometer detects preset situations.
When I tested mine with the trailer hooked up I left the key on, set the gain to 10, taped the slider full on and used my MM to get 7.38v. I then unplugged the trailer with everything else set. I popped out the 7pin, unplugged the connector and tweaked the female connector for the brake lead and put it back together. When I retested without the trailer hooked up I measured 10.5v.
I got to thinking yesterday about pulse width and wondered if I needed the trailer load to trigger the PWM. So I hooked up again and measured. Sure enough, 7.84v. While this little bit might not seem like much, that half volt measured by my MM made a huge difference.
Before, my hemi just over powered the brakes and pulled the trailer with its tires turning.
Now I couldn't move it. The harder I pulled, the more the trailer squatted and groaned.
IMO, at 20mph and 10 gain, sliding the slider over should have locked up your wheels. It would have on my father's 2012 Ram 3500. But this is my opinion. The new ITBM might be programmed in a much different way.
In your case, if you feel the brakes are working satisfactory, I wouldn't worry too much.