Troubleshooting Issues with the Activator IV Brake Controller on a 1997 Ford F-250
Updated 09/09/2011 | Published 09/08/2011
Question:
97 F-250, has the correct harness, etc. Unit only shows a decimal when the brakes are applied, and trailer brakes do not function. When testing the blue wire with a 12 volt test light, the display reads correctly as the brake pedal is applied. Remove the test light, just have decimal again. Sounds like a grounding issue to me, but I have run a continuity test and the ground is continous throughout. FYI I am an electrician, so I have a pretty good idea what I am doing.. Please advise. Need my brakes!!!
asked by: Todd
Expert Reply:
I would proceed by checking the trailer connections on the vehicle and trailer side for corrosion, which could be blocking the signal from the brake controller. The decimal lighting without a reading indicates no conntection to trailer brakes. When using the test light the bulb is supplying a complete circuit and load that the brake controller is recognizing and allowing power to be sent to the test light bulb.
Another good idea is to go over the brake controller instructions, see link, and make sure the brake controller is set up properly.
If the trailer connectors are not the issue, check all of the brake feed wires on the trailer. If the wiring is good and all of the grounds are good, the brake magnets may require replacement. I have linked an article that details how to test the brake magnets, to determine if they are functioning properly.
