Tekonsha Prodigy P3 Shows Low Output Voltage

Updated 03/23/2018 | Published 03/22/2018

Question:

When I push the brake pedal it’s only showing 1.5 amps output current and 1.2 output bolts but when I use the manual lever it shows the full amount the controller is set on. Any help would be greatly appreciated

asked by: Danny F

Expert Reply:

If you are testing your Prodigy P3, # 90195, while sitting still, then the readings you are getting are normal. The P3 is a proportional brake controller, so it will send out an amount of voltage proportionate to the braking intensity of the tow vehicle when using the brake pedal. There is an internal inertia sensor in the brake controller that senses how hard your vehicle is braking and sends a corresponding amount of voltage back to the trailer when you are in a braking situation.

If you are sitting still, the inertia sensor isn't sensing any braking so it will only send back 1 to 2 volts. The manual override lever is there for emergency situations, so it will send out the maximum amount of voltage depending on how far you push the lever.

If you are getting minimal voltage when driving, then I would start by turning up the gain on the brake controller (the up and down arrows on the left hand side). The braking power must be set on the controller to the desired amount of braking power you want when towing. If that isn't an issue, then I would make sure the red wire from the brake controller is installed properly. If you are using a custom plug-in adapter, then this isn't an issue, but if it was hardwired, the red wire should only be spliced to the cold side of the brake light switch or a wire that only shows voltage when the brake pedal is pressed. If you can give me a little more information on your situation such as the year/make/model of your vehicle and a few more details of how/when the brake controller is acting up, I'd be happy to troubleshoot further.

expert reply by: John H