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Tekonsha T-One Vehicle Wiring Harness Installation - 2021 Toyota RAV4

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How to Install the Tekonsha T-One Vehicle Wiring Harness on a 2021 Toyota RAV4

Hey everybody, Ryan here at etrailer. Today, we have a 2021 Toyota RAV4. And we're gonna be showing you how to install the Tekonsha T-One Vehicle Wiring Harness. But before we do that, why don't we check the harness out and make sure it's a product that you're looking for One of the cool things about this wiring kit is how you can keep it stored. In our case, we actually have it stored on the inside of our Toyota. Whenever you're ready to use it, all you're gonna have to do is open up your hatch, come here to your storage compartment, and we can pull it out.

So that's really nice, stays out of the elements, and out of sight when we're not using it. But whenever you are ready to, you're just gonna drape it over your threshold here and close the hatch on it. Now it might seem odd closing the wiring in there but it's perfectly acceptable. It's designed to handle that. So you're not gonna have to worry about hurting it or anything like that.

You do wanna avoid the latch area though. You don't wanna get it hung up in there. But say you're just gonna close it, now we're gonna have plenty of length to be able to hook up to our trailer. Now, if there's someone that wants to mount it outside permanently on the hitch itself, that's perfectly fine too. There's actually a grommet that you can use.

You actually use it during the installation itself to run your power wire. So you can drop this down through that outside and mount it up to your hitch. But with that being said, I mean, trailer wiring is this one of those things that make sense to have on a RAV4. These SUV's are really versatile. I see people doing a ton of different stuff with them and that does include towing some trailers.

So what this is gonna do is allow you to plug into your trailer and give you all those necessary lighting functions, say four way, flat type connector. So really common type connector in that dimension as well. A lot of accessories nowadays even have some lights on them. Particularly cargo carriers and a lot of those have the same type of connectors. So get a two for one there. If you happen to have an accessory or get one on the future that has lights, this will power that up as well. So this kit does use what's called a module box and it's also gonna use its own power wire that runs from the module box to the battery so its gonna have its own power source. That way you're not going to compromise your Toyota's factory wiring. That way if it's short or something like that we're to happen, you're not gonna have to worry about damaging your Toyota's wiring itself. But other than that, you really can't go wrong with it. I'm a big fan of it's the Tekonsha wiring. Everything's really well-built, I actually have a Tekonsha kit on my own car and so I've got faith in them. But other than that, as far as the installation goes it's really not too bad. You gotta plug into some factory connectors and I'll say the most time consuming part is actually having to run that power wire from the back here up to the front. But as long as you stay focused, it shouldn't really give you a whole lot of issues. Speaking of which, let's go ahead and hook it up together now. To begin our installation, we're gonna be here at the back of our RAV4 and what we're gonna need to do is access our tail lights. So we'll start by opening up our hatch and removing any of our floor coverings here. So once you get your floor coverings out of the way we need to remove our center threshold piece here and this more or less just pops up. So you can start at the corner and lift up on it. These are pretty tight. So if it's fight me a little bit one thing you can do is take a trim tool like this and pull out on your weather stripping and then we can get our trim tool under there, pry up and that'll help release the fasteners. So once we get it released, these are the fasteners that I was mentioning and that's what was actually keeping this connected to the body of our vehicle. Now that we have it off, we can set it to the side somewhere safe, so it don't get damaged. So now all we need to do is loosen up the side panels here. That way we can get access to a connector behind our taillight. So we're gonna have a cargo hook that we need to remove. So grab a 10-millimeter socket and pull that out. And we're gonna follow our panel up a little bit and get another fastener out. So following that panel up, we're gonna have a plastic push pin type fastener here in the corner. And you can use a flathead screwdriver, trying to pry underneath the head of the fastener. And then you can get underneath the base and pop that out as well. So with those fasteners removed, we can start to separate our panel and this more or less is pops out. Like our threshold that we removed. So every now and again you might have to take your trim tool and help assist it off. We don't need to pull it completely out or anything like that. This is gonna need to have some space about like that, that way we can get her hands in there and find our connector. So if you hold our panel back, we can locate the connector and the one we're looking for is this one right here. So we need to disconnect it. You can push down on the center of the tab there and get both of them separated. And then we can grab our T-connector side from our wiring kit that has a yellow, brown and white wires to it. And this is just gonna tap right in. So one end of the connector is going to plug into our factory connector there. Same for the other side of it. Over here on the passenger side, I went ahead and repeated that same process. The panel gets pulled apart the same exact ways on the driver's side and the connector was located in the same spot as well. So I just used our T-connector for new wiring that has the red, green and white ends and plug those right in. And this is how it looks. Now we can do is secure our module box. And to do that, I'm just gonna use this included two sided sticky tape to make sure the surface is nice and clean. We'll pop that on there. Pull the other side off. And we're just gonna stick this to the body of our vehicle here. You wanna find a flat clean spot and I think I'm gonna put it right here. Let's go ahead and push it in place. Now we can take the white wire coming out of our module box, gonna have that pre-attached ring terminal that's gonna need to get grounded to the body of the vehicle. So you want a nice clean piece of metal. I'm gonna put it right here and I'm gonna use the provided self-tapping screw to get it secured. Now we need to do is locate a grommet so we can start to get our power wire hooked up. In our case here towards the rear of our vehicle, there's actually a factory rubber grommet and we can utilize that to get our wire through. So since it is a little tricky to see with this panel in the way and everything else, trying to go to this step by step, what I'm gonna do is just drill a small hole in that grommet and that way we can get our power wire ran through there into the underside of our vehicle. I went ahead and just drilled a small hole on that rubber grommet. And then I took the big bundle of black power wire and fed it down to the underside of our vehicle. So when I dropped our wire down through that grommet I left about a foot and a half wire to work with up here. And what we're gonna do is get it ready so we can strip back a little bit of the insulation there. Could I take one of our butt connectors, place it over the end and we can go ahead and crimp it. So here we have the black wire that's coming out of our module box. That's gonna get connected to the black power wire that we could connect to the butt connector too. So work the same, just slide into one end and then crimp it down. And so I went ahead and did just use some RTV sealant around our grommet that we drilled the hole through, that way it's sealed up. And I also use some zip ties just to secure all of our wiring. If you need some sealer, you can find it here at etrailer. Or with that being said, this is how it all turned out. So as far as your four way flat connector wiring goes, what you wanna do is just make sure that it runs out from underneath our panel. We can just keep that in our spare tire area for now. And I wanted to show you how I routed our red and green wire now that had the T-connector on it that goes to the passenger side. So there's actually an indention here in the body of our vehicle. Just tuck that wire in there and just use some packing tape along there to keep it nice and secure. Now we can do simply re-install and secure our panels the opposite way that we removed them. Now underneath the vehicle, we need to route our power wire up into the engine compartment. That way we can hook it up to our power source. So here is where it comes out from our rubber grommet that we pushed it through. I routed it this way towards the front, zip tied it along the way to keep it secure. Now whenever you're riding this, you wanna be sure to avoid any hot or moving parts. And so what I've done, it's a little tricky to see but that wire actually runs on top of our sub-frame. That way it clears all these suspension components and it's going to drop down along this side here. I'll pull this panel down so we can see. So here's where our wire comes up and over our sub-frame and along through here. Now I did lower this plastic panel down just to make it easier. There's a handful of 10-millimeter bolts that you can pull out. And you can drop this down if you need to, but it just continues along this way following those factory lines and continues on underneath this panel as well, right along through here and it just continues straight. It's tricky to see, but just continue straight. So here's our wire right about here and starts to go up to the engine compartment. Now, the way I got it up there is you can take a. It's called a pull wire. So I use a piece of tubing, you can also use a coat hanger, something like that. Drop that wire down from the top side of our vehicle. You can tape the power wire to it, go back up top, pull that wire up and that'll bring our power wire exactly where we need it to go. All right, so now at the engine compartment here. There's where our power wire came up, along our firewall. And I just routed it along the side of our battery here. We'll loop it back around where it ends here. So I strip back some of the insulation, we're gonna do is take a butt connector and put that on. So what I did is just strip back the insulation. You can take a butt connector, put that on over the end and crimp it down. Then we're gonna grab the included fuse holder, make sure that fuse is not installed. Go ahead and cut that in half, strip off our insulation there. And what we're gonna do, one end of it will get connected to our power wire there using the butt connector we just crimped on. The other end of our fuse holder is going to receive a ring terminal. So it works the same as our butt connector, just slides over the end and get that crimped. Now we can hook this up to our battery. All right. So if you look here, we can remove this cover and this nut here, we can pull that off using a 12-millimeter socket. Careful not to lose it. It's gonna take our ring terminal, slide that over the stud, get our nut re-installed. With that tightened down and everything hooked up, we can grab our included fuse and put that into the holder. So I went ahead and just pushed our red cover back over our battery terminal. Just for an extra layer of protection, I also taped up our butt connector with some electrical tape here, and now that this is done, we can get inside the vehicle, plug in a tester and make sure our wiring is working. So I went ahead and plugged in this tester which I suggest using as opposed to a trailer, something like that. That way we can isolate our vehicle and make sure that our wiring is indeed working properly. That being said, go ahead and try our left turn signal, our right turn signal, our brakes and our running lights. And that'll finish up our look at and our installation of the Tekonsha T-One Vehicle Wiring Harness on our 2021 Toyota RAV4..

Bill K.


I believe the Rav 4 Prime has the battery in the back and therefore you don't need to run the power wire forward?

Victoria B.


From what I know, yes the battery in the current model RAV4 Prime is in the rear cargo area.

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