2nd gen - Trailer Brake and Power at 7 pin connector, troubleshooting help request

Hi all-

We have a 2012 Tundra Limited with factory tow package and a Tekonsha voyager brake controller installed. This truck is new to us and I am getting it ready to tow our GeoPro travel trailer.

I have found there is no +12v power and no trailer brake signal at the trailer connector on the bumper. The ground wire is correct and the left/Right blinkers & brake lights work and the tail lights work. I am in the process of troubleshooting and hoping to glean some wisdom here.

So far I have removed the Tekonsha voyager brake controller and checked that the correct wires are connected to the factory harness plug correct wires; that checked out OK. I inspected the 7-pin at the rear bumper and it appears to be factory and unaltered. I have checked the 2 fuses marked "trailer" in the fuse box adjacent to the battery; both fuses are good and there is 12v in the fuse socket. The 7-pin connector appears to be factory, I traced the wires up the frame rail to the electrical junction box on the upper passenger side firewall and did not see any issues with the wire bundle.

When the key is on, I hear a buzzing from under the truck and when I actuate the manual brake on the brake controller, I hear a slight click and the buzzing subsides. This buzzing is coming from inside the transmission pan. Is this buzzing normal? Any idea why the manual actuator on the brake controller would be connected to the transmission?

I also notice the light on the brake controller never illuminates.

Next, I think I will do a continuity check from the the 7-pin connector at the electrical junction box on passenger side firewall, then to the factory harness in the driver footwell where the brake controller connects. I may also bench test the brake controller to see if I get a voltage output on the Blue brake power wire although I am confused abut the buzzing in the transmission pan and the fact it stops when the brake controller is actuated; maybe this is a sign the brake controller is failed which a bench test should reveal.

Thoughts and suggestions welcome, thanks.

 

I would start with all the fuses on this diagram. Looks like the 30A Tow Brk fuse sends power down a black wire to the towing brake controller, which this goes to pin 7 of the connector. If you dont have lights on the controller it may be a power issue.

 

Thank you for the schematic!

 

All seems to be working now. One thing I learned by bench testing the controller is that my it is only active when the trailer is connected (it senses the electrical load) so my testing at the connector was moot. It looks like there likely wasn't an issue, just a learning curve.

Thanks again for the quick schematic!

 

Just picked up a 2012 Tundra 5.7 Have kich panel off but can not see where to plug in the Trailer Brake Jumper Harness which came unused with the truck. Connecting a Prodigy P2 off the old Silverado. Any Help would be greatly appreciated. Will review above schematic.