Weak Brake Response With Prodigy P2 After Installing New Trailer Brake Assemblies

Question:

Hi, I recently installed a new brake set on my trailer. Properly and according to the directions. My Prodigy P2 reads .c when connected and the other LED functions on the P2 boost and 0.0 to 12 power light up properly. Problem: I have very little braking power. And no brake lights when activating the P2 manually. When using the manual lever to increase the stopping power the red led lights show increasing power as does a volt meter connected to the hot black wire to each brake. But the brakes barely hold me back. The shoes are adjusted just a couple of clicks off of tight. The pulling vehicle is a 2007 Dodge 2500 with factory installed towing package. Hope you can help. Thanks.

asked by: Rusty S

Helpful Expert Reply:

Thank you for providing details about the issue you're having with your trailer's new electric brakes not providing sufficient stopping power. Since your troubleshooting efforts have confirmed that there is a correct 12V braking signal reaching the brake assemblies' wiring, my first suspicions are that the brake assemblies themselves either need adjustment to their star wheel (to increase their grab) or that there is an issue within the brakes, such as a short in the magnets. It is also possible that grease can work its way onto the brake shoes. If your brake circuit wiring is too low of a wire gauge this could prevent full current from reaching the brakes.

Make sure that the ground wire from each brake is secured to a clean bare metal surface on the trailer frame, as this is critical to proper operation. You can also try adjusting the star wheel to increase the drag on the drums. Please refer to the linked video at the 17:15 mark which illustrates the adjustment process.

There should be clearly audible drag on the hub when you rotate the wheels. The wheel should NOT spin freely when the brakes are not applied; it should have enough drag (resistance) that you can hear and feel it.

You can also test them separate from the tow vehicle and brake controller by applying 12V power directly to the brake circuit on the trailer plug with one side of the trailer jacked up. The linked photo shows you the two pins that need to make that 12V connection; hot goes to the 7-o-clock pin and ground to the 5-o-clock pin. If the brakes will not lock up when you apply direct 12V power in this manner then either there is an issue with adjustment or the brake magnets might be bad. A linked article explains how to test them.

If you have access to either a different tow vehicle or a different trailer both known to be operating properly you can try substituting one or the other to see if the issue remains. If you can hitch another trailer and its brakes work fine then you know the issue is not likely to be in your truck.

expert reply by: Adam R