If you are referring to the harness that comes with the controller itself (as opposed to the vehicle specific ones available from RedArc), I can confirm that this is not the case, at least not at the time we bought ours (early 2020). When used in conjunction with the factory harness connector that came with our 4Runner, dashboard Christmas resulted as soon as manual control was applied. Splicing the diode into the brake light feed circuit corrected that. Because I already had the Toyota end of the harness (and am quite comfortable doing automotive wiring), I didn't bother buying a completed one through RedArc. Helpful information for others, though. Thank you!

Glad that you enjoyed it! I appreciate it!

I contemplated that spot as I too felt it would be more convenient. The counter-sunk spot had me worried that I might not be able to grab the knob that easily, so i went to the left, which has worked out fine for on-the-fly adjustments. If memory serves, RedArc's listing for that blank doesn't actually show this generation of 4Runner as one of the applications it fits. Thank you for the compliment, glad you liked it!

Since both the 4Runner and controller came with cables and I'm proficient in electrical work, it was easy for me to make my own by joining the two. Good suggestion, as I wouldn't have even thought to investigate the pre-made option.

Appreciate the positive feedback, thank you! I suspect that the installation will be otherwise the same. The pre-collision system was introduced on the 2020 models, and I don't think that at the time many folks had encountered that issue. Although another viewer suggests that newer RedArc Elites come with a diode, I can't say for certain if that's the case, or if RedArc or anyone has updated their information to reflect that. Theoretically, this PCS brake signal feedback error would be a problem with any brake controller, not just RedArc's. I'm a working tech that specializes in electrical, so I just quickly cobbled up the diode work-around, and the controller has worked perfectly since. It just won't activate the truck or trailer's brake lights if I manually apply the controller without also applying the truck's brakes as well. I can live with that compromise. I fully expect that your 2017 will be virtually identical (other than that 2020+ issue) as the interior trim and trailer wiring itself is probably exactly the same. Toyota's changes to these trucks has been incremental for the most part - a plus in my eyes. Your brake lights should also apply with the controller's manual function, of course. Good luck, have fun, and enjoy!

In applications where one of RedArc's blanks will fit, no drilling is required to mount the control knob. Our 4Runner wasn't one of the listed models, but I guessed by the shape that one for other Toyotas was right, and it was. (And will be, right up to the 2023 model year.) Worst case, you'd have to drill a small hole. If your vehicle has blank switches, you could use one of those, and if you ever wanted to return it to stock, you'd just need to find another switch blank. Now, mounting the actual control unit, you might have to drill a hole or two, but I was able to find spots in our 4Runner that lined up well enough that I didn't. (At least any of those holes would be out of sight anyway...) My only "complaint" is that the supplied, numbered bezel prevents the knob from being pushed, or at least did in mine. M pretty sure that RedArc has a new knob style now, so the new one might fit better.

At the time that I did my installation, the 4Runner's pre-collision system was so recent of an addition to the model that there wasn't much information out there. No mention of any of that then, and I merged the RedArc harness with the adapter Toyota left in the glovebox as seen in the video. I didn't notice a diode in that harness, so I guess Toyota didn't see fit to include one. The diode I spliced in was just me thinking on my feet as a tech that does a lot of auto electrical. Our RedArc is still working great - actually had to perform a shorter than comfortable stop on the weekend from about 80K/50mph and I could feel the trailer helping appropriately (thankfully!). If you can isolate the brake signal feed wire in yours you can just backfeed 12 volts in to it to simulate you pressing the brake and eliminate the truck. (The power, ground, and controller output will still be to/from the truck, of course. And the RedArc won't fully power up until it senses a connected trailer, so you'll have to do that or spoof the load with a head light bulb or something. Good luck!

That would definitely be the best solution if you didn't have the interface plug. Not having pre-collision, I'm assuming that your truck was fine having the brake lights activated by applying the controller manually, so probably no need for diodes. PCS did not like that one bit on ours! (Adding the diode to that circuit solved the problem in our truck.)

Update: Towed 2 different trailers and all working well. I would highly recommend buying the Toyota harness (mine didn't have one in the glove box) but if you're in a pinch, these color matches do work.

It was late by the time I'd finished installing and videoing, so when the PCS malfunction occurred and I figured out the solution, I just grabbed a diode I had handy from a container of components I have and made the repair. Never even thought to record it. If memory serves, it's a 1/4 Watt rectifier diode, though you could probably use something with a lower rating as there's very little current applied. It's oriented to permit power from the truck's brake light circuit to reach to controller as an input, but not be fed back out, so no truck/trailer brake lights on with the controller applied manually, but normal function in all other ways. I'd be happy to elaborate if you have any other specific questions about the job.

Our trailer is a single axle rated within a few pounds of 3500. We're probably at that or a few over. Our economy varies considerably with speed. On a trip with a subtle but consistent gain in altitude where we tried to stay with the flow of traffic (110-115 km/h or ~70 mph) we saw somewhere in the 27L/100 km (~9 mpg) range in the trip computer, and nearly ran out of fuel from a full tank in under 300 km. Keeping it closer to 100-105 (65ish) on less hilly terrain still sees us into the high teens to 20L/100 km range (so, closer to 12 mpg). That's also following Toyota's direction to use "S" mode to manually lock out 5th gear. The 4Runner's gearing is such that 5th is just a bit too tall most of the time anyway. This vehicle may be rated for 5000 lbs and would likely move it, but it wouldn't be happy. I'm glad it has the ancient but bulletproof 5 speed auto in most ways, but having 6 gears to choose from would probably help the towing mileage appreciably.

@@2BlackStripes Thank you for the data! An 8sp transmission is greatly needed!

Thank you for the positive feedback!

You're probably 100% right. As stated in the video, the primary purpose for my removing that was not to access the blanks (you could even just reach up from underneath for the lower one for sure, probably the upper ones too), but to mount the brake controller's module. It's possible that I could have done that without pulling the panel as well, however it's simple enough to remove and made my life much easier. Having it out of the way also made filming easier! Now that I've tracked down a Party Mode switch, I can finally put that in to the factory location, and I'll give your suggestion a go for sure. Thanks for viewing, and thanks for the feedback!

Hi Math123, I used the harness supplied with the Redarc controller and connected it to the factory jumper harness that was in the glovebox of our 4Runner when we bought it (Toyota part number 82132-60110). I specialize in vehicle electrical work, so patching a simple harness together was easiest for me. I had a look at Redarc's website to see the harness you've mentioned, and the listing suggests that TPH-021 is for '14 to '19 4Runners. I can't say if Toyota changed their connector for 2020 and newer models, but it is possible. Also possible that the Redarc TPH--021 would plug right in, but cause the same feedback issue, since it's unclear whether a diode is built in to that harness, and 2019 and older 4Runners did not have the pre-collision system and may not have needed one.

It's definitely a solid alternative, and would save having to fuss with mounting the Tow-Pro under the dash of our truck. I decided to go with a unit mounted to the truck, rather than the trailer, on the off chance that I end up towing a different trailer at some point, either my camping buddy's (if his tow vehicle had a mechanical problem while away), or a large utility trailer that I have access to. If that were not the case, or if we had multiple tow vehicles and one trailer (such as a property maintenance fleet sharing a deck trailer), the Tekonsha would be a great choice.

Hi Peter, sorry to take a while to get back, was on vacation! The Redarc Tow-Pro Elite, we got ours from etrailer.com: www.etrailer.com/Trailer-Brake-Controller/Redarc/RED44FR.html The switch blank that did fit our 2020 4Runner (and should fit any 4th-gen 4Runner): www.etrailer.com/Accessories-and-Parts/Redarc/331-TPSI-002.html Cheers!

Toyota rates the 4R at 5000 lbs, which I think is a bit generous, given how it handles the 4k-ish trailer we have, but your Scamp will be an easy tow for it. If the trailer has brakes, I'd still highly recommend a brake controller to use them even at that light weight. In an emergency, every little bit matters. Also aids stability. Happy Camping!

Exactly. We've used it on several trips now and I'm quite pleased with it. I've personally recommended one to a few people now.

Mrs.2BlackStripes likes to be well equipped, so I'm confident that we're over the trailer's GVWR. I try to avoid carrying more than an absolute minimum of fresh water to avoid adding to that weight at least, filling up at the campground if there isn't "city water" hookup. I mention all that for context. The 4Runner definitely knows it's back there, and as per Toyota's recommendation, we tow in "S4", locking out 5th. We also have equalizer bars and a sway brake that I usually use when it's loaded; they do help with stability and rear axle bounce over bumps. Our storage location is under 20 minutes from home, and I just use the factory drawbar to and from, with no issues, so if your trailer isn't bursting at the seams, you may be fine like that. The only quirk I've noticed is likely down to the single axle, and that's a sensitivity to larger vehicles traveling the same direction and their position relative to the trailer. If they're behind the axle (or ahead of the axle), I can feel air pressure pushing the tongue sideways a bit, enough that I have to apply a very small amount of correction to the steering. Unnerving at first, now I don't really notice it. Provided the brakes and controller are adjusted correctly (you probably will end up making minor adjustments to gain as you're traveling), that should be fine too. Just have to remember that even with the trailer helping, your stopping distance will still be muuuuch longer. Good luck, and happy camping!

Similar sound, very different income levels!

Thank you for the link! After looking as closely as possible at the single image provided by etrailer.com, I don't see a diode integrated into that harness, so while it would indeed save joining the Toyota OE connector to the one that comes with the Tow-Pro, I think you'd still find yourself having to splice in a diode in a 2020 or newer 4Runner to keep the PCS happy. It would probably be a nice, simple, plug-n-play for 2019 and older models though - I appreciate you sharing that with me!