Trailer Brake Controller Prewiring

[rfdj]

I plan to put it to the right, next to the console. I would prefer not to drill for the bracket. What I had in my JLUR was a center console tray that I put the controller in.

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[JRunner]

It looks like the 4Runner SR5 has a prewired connection just behind the blank trailer brake controller panel! Huge win for future upgrades here.

hey - any idea what the part number is for the panel you removed in your last pic?

I believe it houses the trailer light and power running board switches should your truck have those options and is on the left side of the dash?

I'm hoping to order another one so I can cut it up to install my tekonsha p2.

 

[Eric]

A previous post on this thread seems to indicate that a REDARC brake controller with the TPH-021 harness should be plug and play using this white connector, has anybody been able to verify that?

 

[Peter_Offroad]

I just plugged the REDARC TPH-021 into the white connector, and it seemed to have all the correct voltages.

On the end that plugs into the REDARC:

• White looked to be ground.
• Black looked to be 12V
• Red seemed to be 0V when brake not pressed and 12V when brake pedal was pressed.

I do not yet have a trailer, so have not yet been able to test that it works - and have not looked at the blue line and whether it flows back to rear of the truck and is in the 7 pin back there.

The 30A fuse seems to be populated in the passenger side engine compartment fuse box.

 

[Peter_Offroad]

I am still working out where I am going to mount everything. The REDARC controller I think I will mount on the metal strut holding the lower corner of the dash on. But none of the switch mounts provided by REDARC (TPSI-001, TPSI-002, TPSI-007) will fit in any of the open locations. So will need to drill an existing one - not easy after taking one of the blanks out. Or it looks like TPSI-011 should fit - if I can get one.
Compounding the issue is that while I did not get the 4 AUX switch option on my truck, it is wired for those switches in the switch locations ( the fuses and the relays are missing in the fuse box). The powered running board location is also wired, even though I do not have that. Seems the possible locations that are truly blank are location H (Trailer hitch light switch location) or between switch B and C which is blank in the manual.

 

[Peter_Offroad]

Controller now wired and installed.

Need to test it with a real trailer with trailer brakes.

Purchased a REDARC TPSI-011 from Summit racing. The TPSI-011 is the correct blank block for the empty slot on the top switch row.

 

[Boobajoob]

Amazing. Thank you for this.

Would this not indicate you could potentially add a Toyota tow tech package at the dealership?

 

[Peter_Offroad]

IMO.
There is a technical answer, which is, it looks like the wiring harnesses are the same, so it is relatively easy to add an after market brake controller, if people want. This is great for us that need to - for various reasons I could not wait for an ideal vehicle.
However it is probably more determined by the business equation. The aftermarket solution was $300 - and there were no instructions from REDARC, nor did they answer my two requests for information. For Toyota, their brake controller controls are in a hard place to access - meaning more of the dashboard needs to come apart. Toyota would need to write the technician installation instructions, maybe train people, stock parts etc. There maybe software changes to link it into the Toyota software. The job is probably several hours - even with instructions, due to the different location and things that need to come apart for their location. It cost me a little under $300 for parts (REDARC Elite controller with TPH-021 then a TPSI-011 later), my labor is "free". What would the economic price be for Toyota - it is probably not $400, which I believe is the installed in the factory price.

 

[RollingRocker]

Controller now wired and installed.
Need to test it with a real trailer with trailer brakes.
Purchased a REDARC TPSI-011 from Summit racing. The TPSI-011 is the correct blank block for the empty slot on the top switch row.

Thanks for the write up and pictures! I’ve been procrastinating installing mine and have had my package from REDARC sitting on my bench for a few weeks now. Think today is the day. When I contacted REDARC to inquire about the compatibility of the prewired harness they indicated that the correct switch blank would be the TPSI-011. So I am glad that I ordered it with the rest of the components.

I drag around a Smittybilt scout trailer which is small and light so it likes to whip around back there at interstate speeds. Especially with the Wyoming wind which never seems to stop blowing. Supposedly the elite controller can help eliminate some of that. Guess we shall see if that is just marketing hullabaloo or not. It will also be nice to have the brake control on the 4x4 roads to keep things balanced.

I never used a brake controller on my Tacoma when pulling this and didn’t really have issues. So it may just be extraneous upgrades but fun to do nonetheless.

 

[Peter_Offroad]

A tip. To get the switch blank out, that I did, I ended up pulling out the top of that part of the dash - need to pull the hard plastic piece off to the top and left as well to do that.
However I don't think that is necessary - having now got the blank out. I think it is possible to get a screwdriver (or two - one for each side) inside the blank and down the sides to the latch and pull them inwards. Here are pictures of the blank, inside and out, and where the latches are.

 

[Peter_Offroad]

Thanks for the write up and pictures! I’ve been procrastinating installing mine and have had my package from REDARC sitting on my bench for a few weeks now. Think today is the day. When I contacted REDARC to inquire about the compatibility of the prewired harness they indicated that the correct switch blank would be the TPSI-011. So I am glad that I ordered it with the rest of the components.

I drag around a Smittybilt scout trailer which is small and light so it likes to whip around back there at interstate speeds. Especially with the Wyoming wind which never seems to stop blowing. Supposedly the elite controller can help eliminate some of that. Guess we shall see if that is just marketing hullabaloo or not. It will also be nice to have the brake control on the 4x4 roads to keep things balanced.

I never used a brake controller on my Tacoma when pulling this and didn’t really have issues. So it may just be extraneous upgrades but fun to do nonetheless.

Those washboard roads up into the Winds near Pinedale, get very very slippery when wet. Good to have every tool you can have when navigating them. I am going to be pulling an offroad teardrop/squaredrop that will be ~2500lbs, so need some brakes in it, both legally and practically.

 

[RollingRocker]

Thanks for the write up and pictures! I’ve been procrastinating installing mine and have had my package from REDARC sitting on my bench for a few weeks now. Think today is the day. When I contacted REDARC to inquire about the compatibility of the prewired harness they indicated that the correct switch blank would be the TPSI-011. So I am glad that I ordered it with the rest of the components.

I drag around a Smittybilt scout trailer which is small and light so it likes to whip around back there at interstate speeds. Especially with the Wyoming wind which never seems to stop blowing. Supposedly the elite controller can help eliminate some of that. Guess we shall see if that is just marketing hullabaloo or not. It will also be nice to have the brake control on the 4x4 roads to keep things balanced.

I never used a brake controller on my Tacoma when pulling this and didn’t really have issues. So it may just be extraneous upgrades but fun to do nonetheless.

Those washboard roads up into the Winds near Pinedale, get very very slippery when wet. Good to have every tool you can have when navigating them. I am going to be pulling an offroad teardrop/squaredrop that will be ~2500lbs, so need some brakes in it, both legally and practically.

No doubt. Washboards are such a part of life around here aren't they haha. Rattle the damn teeth out of your head. I need to get over into that part of the state more. I get distracted crossing the Big Horns and never make it haha! The Laramie range has some awesome and remote access as well. Right around Douthitt Mountain there is come great terrain with rock climbing and mountain biking to be to boot.

 

[Boobajoob]

Here in Canada the ORP (hybrid or gas) doesn't have an option to add the tow tech package to it at all. You need to purchase the TRD Pro, Trailhunter, or Platinum for this. It's just not an option at all for any other trim level.

Was just looking at this wondering if this could open the possibility of adding the entire package, but given how little any dealerships, or 3rd parties, even know about this I guess it's safe to assume I'll be adding my controller and digi mirror as DIY.

I'm heading in this week to have a look at a ORP and will see if I can convince someone to open this side panel so we can have a look. It's in the Canadian user manual at least but I'm not sure if that's specific to the model at all.

 

[Peter_Offroad]

Here in Canada the ORP (hybrid or gas) doesn't have an option to add the tow tech package to it at all. You need to purchase the TRD Pro, Trailhunter, or Platinum for this. It's just not an option at all for any other trim level.

Was just looking at this wondering if this could open the possibility of adding the entire package, but given how little any dealerships, or 3rd parties, even know about this I guess it's safe to assume I'll be adding my controller and digi mirror as DIY.

I'm heading in this week to have a look at a ORP and will see if I can convince someone to open this side panel so we can have a look. It's in the Canadian user manual at least but I'm not sure if that's specific to the model at all.

The side panel comes off very quickly and easily. Good luck.

 

[JRunner]

Hey all,
I'm trying to source a wiring harness for my Tekonsha P2 brake controller and it's proving to be a challenge here in Canada. According to an earlier post in this thread, the Tekonsha 304100 harness works for the 2025 4Runners, although the Tekonsha website still only indicates it's compatible with 2014-2023 model years (https://www.tekonsha.com/product/304100_trailer-brake-control-harness).

A local reputable hitch installer exclusively uses a different 304000 harness for all Toyota and Lexus and has had no issues, but hasn't yet installed on a 2025 4Runner. Tekonsha's site indicates the 304000 is only compatible with 2003-2013 model years (https://www.tekonsha.com/product/304000_trailer-brake-control-harness). The local shop has the 304000 in stock. Visually it looks exactly the same as the 304100.

I have a question in to Tekonsha directly on the compatibility but haven't heard back and it's been over a week. I just asked them again. I'm heading out camping in a couple weeks so anxiety is starting to kick in!

Curious if anyone in this forum has any insights into whether the 304000 harness also works? If I were to purchase and test it out, what's the worst that could happen? My thought is maybe a blown fuse...but I'm not an electrician so really am not sure. A "friend" said it could cause serious damage...so I thought I'd throw it out there to see if there's any intel in the community.

Thanks!

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