Brake Controller Not Sending a Full 12 Volts with Brake Pedal

Updated 05/18/2018 | Published 05/17/2018

Products Featured in This Question

Digital Multimeter with 42" Long Test Leads - LED Display

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$22.17

10 Gauge Wire - Blue Primary - Per Foot

(104)

$1.84

Question:

JUST INSTALLED NEW BRAKE CONTROLLER I HAVE 12 VOLTS WITH BRAKE PRESSED COMING OUT OF CONTROLLER BUT AT 7 WAY 1.5 TO 2 VOLTS

asked by: Robby

Expert Reply:

My first question would be which brake controller do you have installed? If it is a proportional brake controller then this is not uncommon as a proportional brake controller senses inertia from the tow vehicle and then as the name states, applies that proportion of braking power to the brakes on the trailer. Since you are sitting still while testing, the full braking power will not be sent to the trailer with only the brake pedal depressed.

However, in order to make sure there are no faults in the system you are going to want to turn the brake controller settings to their max output both gain/boost and then apply the manual override switch while testing the brake output pin on the 7-way. If you get a full 12 volts while doing this then the brake controller is functioning properly.

If you do not get a full 12 volts at the 7-way while the manual override is applied while at its highest setting then there is more than likely a short in the brake output wire (usually blue) that runs from the 7-way trailer connector to the controller. You can use a multimeter like part # PT89ZR to pinpoint where the drop in voltage occurs. If you cannot determine whether the drop in voltage occurs then you may just want to run a new wire using part # 10-1-1 (per foot).

Let me know if you need further help after the above steps are completed.

expert reply by: Conner L