4-pin to 7-pin and Trailer Brake

[GPSMan]

I had an existing Tekonsha P3 from years ago. Must be a good model. They still make them. Brake switch is hard to reach. And the wires wire tiny gauge. Didn't want to mess with that. Tapped into the 3 rd brake light wire instead. Ran the wires under the center console.

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[GPSMan]

You can use the bracket they give you as a pattern to cut out the hole. I used a Dremel tool. Small tool. But small job.
I could have used all 4 screws but I dropped one in the dark. So will get around to that 4th screw (bolt) later.

I wedged the 4 pin in the gap to the left. Was just BARELY enough room. But will be held indefinitely without fasteners the friction fit was so tight.

The stock 4-pin is held on with spring tabs on the back. Press the tabs to release it.

 

[tomfrommi]

You can use the bracket they give you as a pattern to cut out the hole. I used a Dremel tool. Small tool. But small job.
I could have used all 4 screws but I dropped one in the dark. So will get around to that 4th screw (bolt) later.

I wedged the 4 pin in the gap to the left. Was just BARELY enough room. But will be held indefinitely without fasteners the friction fit was so tight.

The stock 4-pin is held on with spring tabs on the back. Press the tabs to release it.

I'm still waiting on my June 16th (2021) order (it's in transit currently), so I cannot check myself. Where is the 3rd brake light wire that you tapped into? Did you have to purchase additional wire to reach everything? I would assume you would have to. Thanks for posting the picture, that really helps.

 

[GPSMan]

Yes you will need 25 or 30 foot spool of extra wire 14 gauge is good. 12 ga is probably overkill. 16 ga would get er done.

Have to run a wire from your brake device to the the hitch.

Have to run a wire from your brake device to either: brake pedal switch (possible but I found more difficult) or the third brake lamp wire (took a longer run of wire but easier to do).

To get at the third brake lamp I unscrewed it from the outside of the cab. This gives you access to cavity space between the sheet metal and headliner. Using fingers and a fish tape (or coat hanger made straight) I got the wire extension to go between the plastic trim inside, headliner, and outside rear brake lamp.

I found the REAR brake lamps no good since the same bulb as brake lamp acts as turn signal. You don't want your trailer brakes applied when you signal.

FUSE the brake controller.

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