I've seen some bits and pieces of writeup on this, but figured I'd throw my install locations and experience out there.

Parts:
Redarc Tow-pro Elite Proportional Brake Controller
TEKONSHA 3041P PROPORTIONAL WIRING ADAPTER

Locations:
For the dial, I went for a blank on the left of the steering wheel. The brains of the unit went into the driver side of the center console. It wedges in there pretty snugly, but I added a bolt just to make sure it wouldn't move if I was doing some massive stopping.

Routing out the blank:
This was kind of a pain, but with a dremel and some patience it's not too bad. There is a bunch of plastic that needs to be cut from the blank, and then you need to relieve the plastic in the dash slightly to make room for the Redarc dial assembly to slide in. The damage to the dash is fully hidden by the blank, so if someone wants to remove this someday, a new blank would tidy it up and nobody would ever know.

The rest is fairly self-explanitory. IIRC, I cut one end off of the Tekonsha wiring harness and connected wires to the Redarc wiring harness. IIRC again, all of the wire colors matched so it was easy to do it right. The other end of the Tekonsha harness plugged into the stock connector by the emergency brake pedal.

Hopefully the pics come through and hopefully this helps the next guy.

I have not towed with it yet, by the way. I towed a 4 door sedan on a trailer without it because I didn't get it installed in time (which went fine). The redarc
did fire up and calibrate as described in the manual.

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About to install mine this weekend, can you show a picture of where the factory harness is for the TEKONSHA to plug in to?

-Chris

Second above, can anyone enlighten me on where the plug is to install the oem wiring harness that connects to the brake controller. Looked at the owners manual and didn't see any visible connections like illustrated and found a connection bundled in electrical tape at bottom left coming out of the firewall grommet, however doesn't fit the supplied OEM harness.


EDIT: Found it, hidden behind the vertical bundle of wires running in front of the firewall bundle...

Awesome thank you for this post. This helped a great deal. I just finished this on a 2019. The hardest (tedious) part for me was cutting the factory knockout button but what worked for me was using a baseboard cut tool (oscillating multi-tool) and basically put it in a vice and cut it out carefully and just leaving the clips. Dremel would also work like you did but I don't have one so... whatever works! This took me 1 beer.

Drilling the holes was also a pain since I just eye-balled it but you do have some room to play with.

The only other things I did slightly different that may help others:

1) I installed the knob assembly first with the panel off so I didn't have to cut the panel knockout hole plastic. Tighten and insert knob after:



2) I mounted on the foot panel beside the gas pedal but was worried about drilling to screw it in. I decided to use big chunk of velcro to pre-mount it to find the sweet spot on the panel then I drilled small holes in the panel supports to get some small ties through. I think this keeps it mounted tight enough to not cause concern with any vibrations. Just use good velcro and its tough to get it off. I may be wrong so I'll report back any calibration issues.








So the whole thing took 2 beers. Ok... 3. Not bad.

Again, thanks for your post.

Just to add that I also used the factory wiring harness and used some banana (whatever) connectors. Works fine. The wiring diagram for the harness into the Redarc harness I found on etrailer.com: Installing Redarc Tow-Pro Elite in 2018 Toyota 4Runner Using Tekonsha Wiring Harness | etrailer.com



I should have used the recommended heat shrink connectors but I wrapped this up in cable tubing so.. should be fine. DYDD.

Should I keep the 4Runner this mod is high on my list.

They actually have a Toyota blank that you can buy separately. Pop out the old and install it with the knob, easy peasy.

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That would be too easy!

Anyone have issues with controller not detecting trailer with the wiring done with the Toyota supplied harness? Mine is staying in sleep mode and not seeing the trailer.

I have not had any problems with mine. Might check the plug receptacle to make sure the contacts are good?

Mine is doing the same. I wired using the etrailer instructions linked earlier in the thread. The trailer running lights aren’t working, but brake lights and signals are. It also seems that the trailer brakes are working fine.
I wonder if it’s because the etrailer instructions say to leave the solid green wire not connected? I’m going to experiment today.

Update. I have tried the wiring method mentioned on the etrailer site using the factory Toyota jumper harness: Installing Redarc Tow-Pro Elite in 2018 Toyota 4Runner Using Tekonsha Wiring Harness | etrailer.com. Using this method, brakes, brake lights, and turn signals worked fine, but the trailer running lights did not work when the 4Runner headlights were on.

I tried also attaching both the solid green and the yellow-green wires from the Toyota jumper harness to the red wire on the Redarc harness. Using this method, the turn signals work, and the brake lights work as long as the headlights are off, but when the headlights are on the brake lights don't work. Additionally, with this configuration, I get an ABS and Traction light on the dash.

I'm open to suggestions from you experts out there. At this point, I think I may have to break down and get the Tekonsha 3041P Adapter and give that a go. I will note that I'm using a 7pin to 5pin adapter for the trailer hookup, but I wouldn't suspect that would cause any issues.

So I wanted to give my experience.

I installed with the OEM harness, leaving the green wire isolated (folded back and heat shrink/shrunk).

It seemed to connect properly, flashed blue and green for a while then went solid blue (about 2 weeks ago installed).

Then I hooked up our trailer this weekend (test run) and it started to have some weird behaviors. All sorts of flashing lights, brakes worked but if I held the brake overide long enough, multi terrain select would error on the dash (along with ABS).

So, I have a tekonsha harness on order and hoping it will resolve my issues. I love the look and factory feel of install (used the OEM knockout plate - no drilling) but really disappointed it's not working right now. I will update if the tekonsha harness fixes my issues.

I wanted to get this controler and wanted to see if anyone has figured out the wiring? I have a 2018 with the factory connector. I am waiting on getting this since I saw this tread with issues getting to to work.

Update...

Okay so after installing the Tekonsha harness I've had better success.

Controller proportional mode and user mode both work. Override button functions the brakes (trailer only) but NO brake lights come on (either truck or trailer). When I brake from the truck, all lights function properly and both brakes engage properly.

If anyone has any ideas I'd be happy to hear them.

I will say tho the tekonsha harness is MUCH better than OEM.

Any updates?

I just picked up the Redarc controller as well for my 2020 ORP, and am trying to confirm which wiring harness to use, as the one that came with the 4Runner has 5 wires, but the Redarc harness has 4. I tried calling Tekonsha, but they have no details on the 2020 compatability. I called my local dealer, and they advised to call Tekonsha...

Curious if anyone with a 2020 4Runner has completed this install, and which wiring harness was used (and if all of the lights on the camper work successfully).

Thanks!