Troubleshooting and Testing 2015 Ram 3500 Factory Integrated Brake Controller

Question:

I have a 3 axel toy box I am pulling, at the truck plug with the controller at 10 and 100, I am getting 7 volts. At the #3 axel I am getting 4.5 volts, the brakes are not working at all, is it the stock brake controller? Thank for looking

asked by: Steve P

Expert Reply:

The stock brake controller on your 2015 Ram 3500 is not giving you the proper voltage for safe braking. When you test the 7-way at the 5 o'clock pin when engaging your manual override, you should be getting 12 volts. If you are testing without the manual override you aren't getting a correct reading as the brake controller is proportional and not needing to send more power because you aren't moving.

If you are hitting the manual override, use a tester like # PT89ZR to test without the trailer connected at the 7-way as listed above. If the reading there is good, then we can check the trailer brakes. If the reading there is bad, then you will either need to replace bad wires or a bad controller. If upgrading your controller, I recommend the Prodigy P3 # 90195 which will be able to help you with these diagnostics in the future. The Ram wiring changed in 2013 to the current system, and I've attached an article to assist with adding an aftermarket brake controller if needed.

To test the amperage at your brake magnets, I've attached an article to help, but a triple axle trailer will read between 22.6 and 24.5 amps when working properly. If you read more the magnets are bad and if you read less the leads to the magnets are bad.

expert reply by: Jason S