Help fot tapping brake switch for brake controller

Hi,

I have a 2016 2WD that came from the factory without any installed wiring for towing a trailer and certainly no pigtail hidden behind the dash.

I first installed a cat 3 trailer hitch to have a more rugged hitch.

I also got an OEM plug (7 and 4 pins) and a Hopkins OEM harness wiring kit to connect to it.

I am using a Curt custom wiring harness sold for a 4-way flat plug and then running the additional wires. For electric brakes, auxiliairy power and backup lights. Using also a Reese Brakeman IV Brake Control. Am running all the wires myself and splicing them to make it work like an original tow package.

Except that I tapped the wrong brake switch wire (black) to feed the brake signal to the brake controller. It's clearly wrong because the electric brakes are on even when I don't press the brake pedal.

I am looking for help in identifying which wire to tap into for the brake signal to be sent to the brake control when I press on the brake pedal. I tried to make sense of it but cannot and hope one of you guys have the correct answer.

Has someone done the same installation from scratch? If yes, where and what wire did you tap?

Thanks!

Just to be super clear, it's a complete custom wiring and controller installation as my truck, as sold, had no wiring at all for a trailer with or without electric brakes.

 

This is the schematic for the factory tow package. The red arrow is the brake signal. The circled box is the factory tow controller connector.

 

Hi Speedfreak and thanks.

It might seem obvious but not to me as I am having trouble locating where that wire would be since my truck does not have a controller.

I am starting to think that it's not so crazy to run a wire to the back lights and tap the brake wire right there!

 

Hello and welcome to TacomaWorld.

You can find the wire off the brake switch located high up on the brake pedal. Under the dash this is the easiest location to find it.

 

Gracias Caribe Makaira but aren't you just showing me the pigtail for plugging in a brake controller of a truck that came wired for the tow package?

My brake switch is right behind the brake pedal, its connector is square and no blue wire there.

 

Thanks for the welcoming words!

Solved!

I had tapped the black wire (my mistake, bad testing protocol) in the brake switch. The blue wire, now the one tapped, is working great.

Thanks for your support!

 

If you have a voltmeter or a test lamp, probe the wires. One will be constant power. One will be switched, when the brake is applied. The switched wire is your signal wire to the brake controller. Tap into that one for your connection.

 

Redid my testing with a test lamp. My apologies as the blue wire was right there all along but I must have been missing it as it clearly is switched when the brake is applied.

Thanks so much!!!

 

I am installing a Prodigy 3 controller, however, there is no tow package, so the adaptor plug is not powered, and the brake light switch on the pedal mechanism has 4 wires, 2 constantly hot, and two - yellow and purple/white which do not power up when the pedal is pressed. Help, please! Bob

 

It's usually hidden behind the bundles of wires.
But the stop switch wires are NOT the wires the system requires. It needs the output of the Stop Lamp Control Relay.

P.S. This is the 3rd Gen part of the Forum, you have a 2014...

 

Whoops newbie here has the wrong generation of Tacoma, so will seek the wisdom on the Gen 2 forum
Salty

 

Hi All,
Still trying to find the wire from the switch, or the brake relay, for the trigger (red) wire on my Prodigy 3.

 

Look for this on driver's side.

Slot #4 is the STOP feed.

 

The rest of that plug is the other connections needed for the controller, isn't it? So he would just need the adapter harness from that plug to his specific brake controller