Correct Brake Controller Output Voltage When Tested at Full Power

Updated 07/10/2017 | Published 07/07/2017

Question:

How much voltage should be coming through the plug on full gain setting on a 2006 dodge 3500. At dealer and said a little over 7 volts is normal. I pull a trailer that weighs around 20,000 lbs.

asked by: Todd

Expert Reply:

If you are referring to an OEM trailer brake controller's output voltage, when this is set to maximum gain/boost the voltage reading at the 7-way should be close to 12 volts. Brake controllers have both power and boost settings and if both controls are set to maximum for testing purposes you should read more than 7 volts at the brake circuit contact on the 7-way. The way to test is to use the manual override lever on the controller which will cause it to generate the selected output level even when the truck is not moving.

You may care to refer to the linked articles on testing and troubleshooting trailer brake controllers.

expert reply by: Adam R