Brake controller harness for 4th gen Tacoma?

[pfosx]

@Rkando104, did you get this resolved? If so, hoping you can share with us all. Thanks!

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[jharger]

There was a thread about a year ago on installing a Redarc brake controller with instructions attached as a word document. I used it and added an improvement I discovered. The procedure had you cut into a harness in the drivers side rear door opening to get a brake signal wire. In hindsight I think you could also tap into the wire at the rear light fixture on either side. (I did that for a third breaklight on a camper shell)
Like many here, I was really disappointed to learn the plug under the dash was no longer there. The 4th gen truck has a totally different harness to go with the LED lights and bells and whistles that are now standard. But Toyota did us a mis-service making it hard like it is.

 

[elitemgtac]

Hi Everyone,

First time posting here.

In the last 6 months I have been looking for information on how to hook a wired trailer brake controller. I’ve read this thread and the redarc instruction many times and I was not totally satisfied.
I did not like the idea of cutting the third brake light wire. It is such a small gauge. And yes I can hook up the power to the battery. But I had an issue in the past with another truck where the battery was getting slowly drained by my brake controller as it was always powered.

So I found you can hook up the brake pedal signal to a free spot in a junction box on the driver side B pillar.
And I used the “battery” wire of the 7 pin trailer plug that passes through the cabin to get my power (it’s already switched, works only when the truck is On. and it is fused up to 40 amps. So plenty enough to power brakes)

So I made myself a plug in wire harness. No cutting necessary at all. and it all contained inside the truck.

I took pictures and made a 26 pages document to explain how I did it. Where to get the pins to hook to the toyota factory harness. You can always cut wire if you prefer. It’s up to you.

I did not include much picture on how to remove trims. Maybe later in a future version. I hope this will help someone.

See my instruction here: https://docs.google.com/document/d/...r9gwPvyvecuJ-GpnqtKinVgBIDyXp3uSpCmB37AMa/pub

 

[jharger]

Hi Everyone,

First time posting here.

In the last 6 months I have been looking for information on how to hook a wired trailer brake controller. I’ve read this thread and the redarc instruction many times and I was not totally satisfied.
I did not like the idea of cutting the third brake light wire. It is such a small gauge. And yes I can hook up the power to the battery. But I had an issue in the past with another truck where the battery was getting slowly drained by my brake controller as it was always powered.

So I found you can hook up the brake pedal signal to a free spot in a junction box on the driver side B pillar.
And I used the “battery” wire of the 7 pin trailer plug that passes through the cabin to get my power (it’s already switched, works only when the truck is On. and it is fused up to 40 amps. So plenty enough to power brakes)

So I made myself a plug in wire harness. No cutting necessary at all. and it all contained inside the truck.

I took pictures and made a 26 pages document to explain how I did it. Where to get the pins to hook to the toyota factory harness. You can always cut wire if you prefer. It’s up to you.

I did not include much picture on how to remove trims. Maybe later in a future version. I hope this will help someone.

See my instruction here: https://docs.google.com/document/d/...r9gwPvyvecuJ-GpnqtKinVgBIDyXp3uSpCmB37AMa/pub

Nice job, I knew those connections had to be in there somewhere. I may have to rewire my Redarc controller installation. I put a diode between the controller and the brake signal wire to prevent any feedback from the controller to the truck electronics when I use the controller to apply the trailer brakes.

 

[elitemgtac]

I did not put a diode. It's not a bad thing to put one though.

One thing I notice though, if I use the controller to apply the trailer brakes, the brake light in dash light up (and probably the brake light in the back too). I think OEM controller does that too.
I'm not quite sure how the truck knows that but.. This is cool

is yours doing that with the diode? I thinking it's something more on the output wire that goes to the brake.

 

[Sagebrush]

Crazy good work.

 

[jharger]

I did not put a diode. It's not a bad thing to put one though.

One thing I notice though, if I use the controller to apply the trailer brakes, the brake light in dash light up (and probably the brake light in the back too). I think OEM controller does that too.
I'm not quite sure how the truck knows that but.. This is cool

is yours doing that with the diode? I thinking it's something more on the output wire that goes to the brake.

I'll plug in the trailer this weekend and try it. I did notice that Redark sells a pre-wired diode for some installations.

 

[jharger]

I did not put a diode. It's not a bad thing to put one though.

One thing I notice though, if I use the controller to apply the trailer brakes, the brake light in dash light up (and probably the brake light in the back too). I think OEM controller does that too.
I'm not quite sure how the truck knows that but.. This is cool

is yours doing that with the diode? I thinking it's something more on the output wire that goes to the brake.

Interesting, when I use the controller to apply the trailer brakes no lights come on. (I have the brake lights on the dash turned off). But then the only reason to apply the brakes via the controller is to stop a sway or to set the gain.

 

[pfosx]

Hi Everyone,

First time posting here.

In the last 6 months I have been looking for information on how to hook a wired trailer brake controller. I’ve read this thread and the redarc instruction many times and I was not totally satisfied.
I did not like the idea of cutting the third brake light wire. It is such a small gauge. And yes I can hook up the power to the battery. But I had an issue in the past with another truck where the battery was getting slowly drained by my brake controller as it was always powered.

So I found you can hook up the brake pedal signal to a free spot in a junction box on the driver side B pillar.
And I used the “battery” wire of the 7 pin trailer plug that passes through the cabin to get my power (it’s already switched, works only when the truck is On. and it is fused up to 40 amps. So plenty enough to power brakes)

So I made myself a plug in wire harness. No cutting necessary at all. and it all contained inside the truck.

I took pictures and made a 26 pages document to explain how I did it. Where to get the pins to hook to the toyota factory harness. You can always cut wire if you prefer. It’s up to you.

I did not include much picture on how to remove trims. Maybe later in a future version. I hope this will help someone.

See my instruction here: https://docs.google.com/document/d/...r9gwPvyvecuJ-GpnqtKinVgBIDyXp3uSpCmB37AMa/pub

Outstanding work! Thank you very much for sharing elitemgtac! I now know what my spring project is

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