Troubleshooting Tekonsha P3 Installed With ETBC7 on 2004 Honda Pilot

Question:

I used your instructions to install the ETBC7 kit to power my Tekonsha P3. Everything worked fine for 2 years. Last week I came out and the P3 was backlight was flashing on and off. I called Tekonsha and they said it was a bad circuit board and sent out a new unit great customer service. I plugged the new unit in and it wont light up at all. I tried the older P3 unit and now it no longer lights up. So now I suspect theres no power coming in. Where should I start to diagnose the problem. Could the 20 amp circuit breaker be bad or need to be replaced? Could wire corrosion cause this? Do you have any other ideas to test?

asked by: Ben H

Expert Reply:

When Tekonsha sent you the new P3 did you install it like you were installing a new unit or did you simply replace the actual unit on your dashboard?

Corrosion could have actually fried out your original P3 circuit board. If you have corrosion on your positive battery terminal which is the power source for your brake controller, inadvertent signal could have been sent to the brake controller intermittently therefore creating the flashing that you were seeing on your LCD. The corrosion could have also sent a surge of power to your brake controller which in turn could have burned out your circuit board.

If you did not install the new wiring with the new brake controller one of two things could have happened. First, when you hooked up the new P3 there could have been an instant surge of power and zapped the brake controller immediately burning it out before you even got a chance to use it. The other possibility is that the corrosion is so bad that no signal is getting through therefore your new brake controller is not receiving any signal to power up.

First check the black wire on the controller with a circuit tester such as # PTW2993 to verify you are getting signal. If you are not receiving signal, then it is time to check the positive battery terminal connection. If you are receiving signal, then your brake controller is faulty.

Corrosion is typically a whitish/greenish color. With your vehicle off, use a small, wire brush to break off the corrosion that has built up around the terminal. Install new wiring for your new P3 and it should work just fine.

If your circuits either had a short or were overloaded (which could have happened because of the flashing of the LCD) then your circuit breaker would trip, and it resets itself.

If after re-wiring your new P3 brake controller it does not come back on, you may have another bad controller.

I have attached two FAQ articles. One article covers basic brake controller and the other has troubleshooting tips.