Brakes do Not Work When Using a Hopkins Brake Controller on a Dodge Ram 3500
Question:
I installed a hopkins brake controller in my Dodge Ram 3500 SRW about 2 years ago and it was working great. I had not pulled a trailer with the truck for about 8 months. I purchased a new trailer and when I went to pick it up I plugged in the cord and no brakes. If I step on the pedal I get no readout on the controller and if I manually hit the button on the controller the readout is working but still no brakes. I used the quick hookup harness that Hopkins made for my Dodge and I check it for power and its up to the controller but nothing out of the controller. I took my old controller back to where I purchased it and Hopkins is warrantied for life they gave me a new controller and same thing. I took the plug apart at the rear of the truck and its dry no corrosion looks great. I am stumped the people at Hopkins also had me check the center high mounted rear stop lite fuse as they claim thats what powers the unit my fuse was fine but I am stuck and do not know what to check next. I hope you have a Idea I have not tried yet. Thanks
asked by: John C
Expert Reply:
Since we know power is reaching the brake controller and we know the brake controller is most likely not the problem, the issue has to be somewhere on the brake output wire either on your truck or on the trailer. This is the blue wire going from the brake controller to the trailer connector.
The next step I would take is to use a circuit tester, like part # PTW2993, or a volt meter to test for power at the trailer connector on your truck. You will want to test the pin in the 5 oclock position (see photo). Set the power on the brake controller all the way up and have someone hold the manual override. With the manual override pressed, you should see power or approximately 12 volts at the 5 oclock pin.
If you have no power on that pin, then the issue is definitely on the truck somewhere between the trailer connector and brake controller. Inspect the wiring as far up on the truck as possible. Look for any sections of wire that may be cut, pinched or damaged. If the wiring looks good, cut the blue wire about 6 inches back from the brake controller and test for power there. If you have power there, then the issue is somewhere between that point and the trailer wiring. I recommend just running a new 10 gauge wire, # 10-1-1, from that point back to the trailer connector bypassing the truck wiring. If you do not have power on the blue wire, then the issue would have to be the brake controller.
If you have power on the 5 oclock pin on the trailer connector from the first test, then the issue is likely on the trailer. Inspect the wiring going from the trailer connector back to the trailer brakes. It may be possible that this wire was severed or is not connected in the trailer connector, which would explain why the brake controller does not sense that a trailer is connected.
You should see two wires at the brake assemblies. One wire should be grounded to the trailer frame and the other wire should be connected to the electric brake power wire coming from the trailer connector. I have attached a help article on trailer wiring for you to check out. It shows how electric trailer brakes should be wired.
If you are unable to find the problem or a solution, let me know what you come up with after following these steps and we can take further troubleshooting steps.
