Tekonsha Prodigy P3 Seems to Work but No Trailer Brakes

Question:

Q1. with P3 installed, how to power off when not in use? Q2. After installation, no trailer breaks. 05 tundra has trailer pkg wired. P3 diags reflect volts/power to the breaks w/o any error messgaes? Suspect not enough power sent to breaks or breaks need to be adjusted. Whats acceptable range of power to breaks that diags should reflect? Again, no errors reported and the amps/volts are scaling relative to breaking pressure but sitll no trailer breaks. used trailer - both axles have breaks only one of them wired Cannot activate breaks manually either with controller.

asked by: Randy K

Expert Reply:

After 15 or so minutes of inactivity, the P3 will go into a sleep mode. When the controller is in this mode, it draws only a very tiny amount of power that is not enough to discharge the battery.

If you are still concerned, you can always unplug the controller from adapter wiring using the connector at the rear of the controller. I would recommend doing so if the vehicle is going to be left for long periods of time.

If everything is checking out ok, and the controller is not showing any error messages there are a few things that could be causing the problem. With the gain on the controller turned all the way up, it should be putting out 11 or 12 volts as measured at the pin on the trailer connector. This should be tested while the manual switch activated. If testing at the pin confirms this, the problem exists on the trailer. As a start, I would recommend making sure the trailer brakes are adjusted correctly.

To adjust the brakes, jack the trailer up and place on jack stands. Make sure that the trailer is not being supported by the axle or suspension components. On the rear of the brake backing plate, there is a small rubber plug that covers the adjusting slot. Remove the plug, and use # W80630 brake adjusting tool to tighten the star wheel until the wheel is very difficult to turn. Then rotate the star wheel in the other direction until the wheel will spin with just a slight drag. Repeat on all brakes.

I would also make sure that the brake pads are still good, as well as the magnets. Pull the drum off, and examine the brake magnets. If you can see any of the copper windings through the face of the magnet, they will need to be replaced.

I will link you to our Brake Controller FAQ page as well as the instructions for the P3, in case you do not have them handy.

expert reply by: Mike L