P3 Brake Controller Works with Manual Override But Not Brake Pedal on 2007 Chevy Tahoe

Question:

Hi there, I have the Tekonsha P3 installed on my 2007 Chevy Tahoe and Im having some issues with it. The brake controller is wired up fine, and I checked the connections with a digital meter. The issue is when I press the brake pedal, the Stoplightinch voltage changes from 0.3 volts DOWN to 0.2 volts???? and no out put power is sent to the trailer. BUT, if I use the manual lever on the brake controller, the power output to the trailer goes up to my set limit, and the Stoplightinch voltage jumps to 12.0 volts. is that normal? Is it a bad controller since the wires from the pig tail under the dash workI checked with test light?? Also, I checked the voltage at the 7 way connector when the manual lever was switched and every looks great. Bottom line is there is no response from the pedal. What could be wrong?

asked by: Eric J

Expert Reply:

I assume that you are testing the P3 # 90195 while your 2007 Chevy Tahoe is parked. The controller will not send back power to the trailer brakes if it does not sense any deceleration. If you take the trailer out and the brakes work fine with the brake pedal then that was the problem.

If the brakes still do not work then something else is going on. The red brake controller wire is an input wire, primarily, and only sends voltage back on that wire when the manual override is used so that the Tahoe brake lights will come on when using the manual override.

Based on what you have described the controller is working properly. On your Tahoe there are 5 wires in the tow package wire bundle under the dash. Usually, the brake controller's red wire will go to the light blue/white wire in this bundle. But if that wire is not showing power when the brake pedal is pressed then look for an orange wire in the bundle and try it instead.

expert reply by: Michael H