4-Way trailer harness connects to your tow vehicle to control trailer light functions. Wishbone-style harness comes with 2 tail light wires split for simple wiring.
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Specs:
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Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.
Hey everybody, how's it going Today, we're gonna be going over and showing you how to install the Wishbone 4-way 25 foot trailer wiring harness. So this trailer wiring harness here is gonna be the perfect option for any trailer up to 25 foot. Now, if your trailer isn't that long, it's perfectly fine. We would just go ahead and trim off the extra which is actually what we had to do for this particular application. But so long as it's not over 25 foot, this is gonna be a great kit for you. So this particular kit provides a standard 4-way flat, also referred to as a 4-pole trailer connector.
This is the most common type of trailer connector and the one you're gonna be using if you don't have electric brakes on your trailer. If you do have electric brakes, you're actually gonna be using a 7-way so you wouldn't use this. But for every trailer without a 7-way, it's gonna have this standard 4-way. This is the most commonly and widely used one. So a 4-way trailer connector is gonna transmit the running light circuit.
That's gonna transmit the stop and turn signal circuit for both the driver and passenger side. And there's also gonna be a pin on there for ground. So those are your four total of circuits there. This particular one is a Wishbone configuration. So what a Wishbone configuration is, it basically means there's gonna be two running lights one for each side.
Some 4-ways don't use that Wishbone and they just have a running light wire coming from the front to the rear. Just one wire and then they splice into the two running light circuits at the rear. So it really doesn't matter which you have. We can either run a running light wire for each side or just one and then tie it together at the rear. This one here, there's a wire for each side.
I kinda prefer this. It makes it a little bit easier. But again, you can use it no matter what your trailer has. So this kit has many different uses. Some people, their taillights are getting older. They're cracking, they get sun damaged and they're gonna replace the taillights. They figure that might as well replace the entire trailer wiring harness, which is what we did here. Or if you're building a trailer, it's gonna be an excellent option for that. Now over time, the jacket on those wires can get hard and crumbly exposing the bare wires underneath causing shorts. So that's a good time to upgrade as well. Really, it just really gonna be by age or if you're replacing other components. This is great kit here just to add to your complete set up there so you can make sure everything's working properly and you don't have any lighting issues down the road. So keep in mind, this wiring harness is compatible with both standard and LED taillights. We actually upgraded the LED taillights on this trailer. So it's gonna work great with both. The wire size is gonna be adequate for both of those types of bulbs. So now that we've gone over the wiring harness a little bit, let's go ahead and show you the installation. So first step of your installation, you're gonna go ahead and remove your old wiring harness here. You can see, we have a nice bundle here. It's quite messy. Now you can be as neat or as messy as you want when you're removing this. I end up just cutting a lot of this off 'cause I knew we weren't gonna be reusing it. So it was much faster just to cut everything off and then pull it all out. But now that we've got all the old wires out, we'll go ahead and start running the new ones. So next we're gonna take our wiring harness here and just untangle it as best as we can. So this is actually known as a Wishbone wiring harness. Now what a Wishbone wiring harness means is there's gonna be a running light circuit on each side of the trailer. So normally, they'll tie the running lights in at the back of the trailer, then they'll just run one wire up to the trailer connector. Here you actually have two brown wires for the running lights that go to the back of the trailer connector. So doesn't really matter which one your trailer uses. You can install this either if it had a Wishbone before or just had the standard one. So our two white wires here, these are for the ground. These run back to each taillight assembly. Our two brown wires, that's what we talked about. The Wishbone design. One goes to the driver taillight assembly. One goes to the passenger. And we have our yellow wire here, this will go to the driver's side. And then the green wire will go to the passenger side on the right. So what we're gonna do is we're gonna take our wiring harness here. Now I like to make things look a little bit cleaner. So I'm gonna take some wire loom and I'm gonna install it on the first couple feet of our wiring harness here. Just again, to make it look a little bit nicer. You guys don't have to do this, but if you have some laying around, it's worth the extra time to make it a little nicer. But once I get this on, I'm going to leave a couple feet at the tongue here 'cause you need to keep in mind that you need to have clearance to make turns and you want have enough to reach so you can reach your truck depending on your configuration. So give yourselves a little bit of extra wire here at the front. And the way you can do this to make sure that you don't short yourself, just kinda take it here and just wrap it around the tongue jack here or the trailer coupler. Just make yourself sure that you give plenty of extra. So now what we're gonna do is we're gonna route all of our wires from the front to rear here. So again, our wiring harness does kinda split in two. These three wires here with the green wire that's gonna go to the passenger side. And these three wires here with the yellow wire, that's gonna go to the driver's side. So just keep that in mind when you're routing them. But we're gonna go ahead now and get that done. And then we can show you how we did it. It's really gonna vary depending on how everything looks underneath. So the step by step really isn't gonna do you guys too much good because again, your trailer can be different, but the overall basis of it should be pretty similar. So we'll go ahead and show you that once we have it all done. So we've got our wires are routed now. Now right here just directly behind the jack tube, I used the little ring clamp here along with the self-tapping screw. That's just gonna secure our harness here so it's not falling down. But once I come from there, I'm gonna go directly down and then we're gonna be pretty much tying these to the bottom of the frame. So you're gonna see these little metal clips here. So I recommend picking these up with your wiring harness because there's really not a lot of ways to secure the wires to the bottom of the trailer. Granted that's gonna depend on your trailer, but most of the time, you're gonna have a flat lip on a frame rail. And the way these work is there's teeth on them. So you hammer them onto the bottom of the frame and there's a smooth side that you guide your wires through. So basically they just make a nice convenient way to hold your wires there without them dangling down, without requiring any modifications. Just a simple tap to the hammer and they're nice and secure. The teeth bite on there so they don't move. And then you can just use your wire to guide them through. But we're gonna use more of these here and just work our way down the frame rail. You can see our wire here. We have another one of those metal clips. And then from about this point on, we're gonna have to jump under the trailer. So we're underneath the trailer now and you can see we have our wire just tucked nice inside the frame rail here using those little clips that we showed you. And then for our particular trailer, we have these cross beams here. There's already holes drilled in there. We just enlarged them that way I could sneak the wires through that beam. If you don't have those, you don't have to worry about it. You can go around them. Again, a lot of this is gonna be specific to your trailer. Not everyone is gonna look the same underneath, but again, most of them are gonna have this frame right here so you can use those little ties. But we're just gonna keep working our way back to the frame. So we're gonna route our wire to about this point here. And then we're gonna come back outside the trailer because we actually have the clearance light that's gonna be installed here. Now, chances are you have several of these on your trailer. Some are gonna have more than others but the locations that you do have the clearance lights, here's what we're gonna be installing. It's just gonna mount up like so, so you need to make sure that you stop and give yourself some extra wire here whether you make your connections now or you make them at the end. What we did is we went ahead and cut our wires and we attached the two ends to one of these butt connectors. And then these two ends of the butt connectors, we're gonna attach to our light here. So we're gonna do that a little bit later. We're not gonna do it right now. If you wanna wait, you can just coil up, give yourself some extra wire to work with and then continue running your wire to the rear. But again, we need to do this each time that we have a clearance or side marker light on the trailer. You could have several so just be aware of that when you're routing your wire. So we don't have any more clearance or side marker lights. We just have the one on each side. So we can just now route this wire to the end here. Now this is a single axle trailer. So we're just gonna keep following our wire here. We have another cross beam that we went ahead. There's a pre-drilled hold there. We just drilled through it. So this area here around the suspension, the axle, you wanna be careful that you secure the wire. You don't want the wire getting tangled up in the leaf springs or anything like that. So directly over the axle, I have another one of those wire clips. Now you can use as many of these as you want or few as you want, but you do need to make sure your wire's not gonna be dragging on the ground. But from here, we're gonna go up and over the axle, we have another cross beam back there. And then directly after that cross beam, that's where our taillights are gonna be. So we'll jump outside the trailer. We'll show you where that wire comes out. So we've got our wiring harness. The end run back to where we have our taillight here. Now we're working on the passenger side. So again, we need to have that green wire. So what we're gonna do is we're just gonna simply connect our three wires here to the three wires coming from the back of the taillight. Now your taillight may be a little bit different in regards to wire colors, number of wires, because that's gonna come down to which specific taillight you have. But the three wire design of this one is pretty standard. This is gonna be most commonly used. So this is probably what you guys are gonna have as well. So we went ahead and just used something to secure our wire here, a little ring clamp, just so it's not dangling on the ground. So I'm kinda nut about this stuff. I always like to make sure that we have tons of security points along the way to secure our wire. That way it doesn't drag down, get tangled up in anything. I just like to go a little bit overboard even sometimes on securing the wire. But what we're gonna do now is we're just gonna attach our three wires here to our three wires here. We are, however, gonna make a ground jumper which will show you in the second. But in order to do all this, we are gonna need some miscellaneous butt connectors such as you see here as well as some electoral tape, some ring terminals. And if you guys have this at home, great. If you do a lot of wiring, chances are you do have these. They're pretty common. You could even pick these up individually in town. But we actually sell a kit here. That's gonna have all these miscellaneous connectors. All the ones you need and some of the ones you might not need. And it's also gonna have a crimping tool. So it's pretty cost effective. I would recommend picking it up along with your trailer wiring harness here. Just so you have everything right here when you need it. But with that being said, we'll go ahead and start making our connections now. We're just gonna strip some jacket off of each of these wires to start and then we'll begin making our connections. So our green, this is for the stop and turn signal circuit and then our brown, which is for the running light circuit. We can just connect those straight to one another using one of these butt connectors. You wanna use the blue ones here. I always like to twist those strands there. That way, they don't kinda fray and go to the side when you're sticking them in. So there's that one ane we'll have these running light wire. And get that crimped on there. And every time I crimp a wire, I always like to just give it a little tug. Hold on the butt connector and give it a little tug. Make sure it doesn't pull out. But we've got those two wires taken care of. Now we have our white wire which is just for the ground. So what I'm gonna do is I'm actually going to attach these together and then connect them to a ring terminal, which is this here. And then I'm going to screw that ring terminal into the frame of the trailer there to act as our ground. So you will need a self-tapping screw in order to do that. Well I think I'm actually just gonna attach it right up there. That seems like it's gonna be a good location for us. So there we go. That looks pretty good. What I'm gonna do now is I'm gonna take some of our electrical tape here. I'm just gonna clean up all these wires. You wanna make sure that you cover those butt connectors. You don't want any water getting in there. Basically, just making it look a little bit nicer. When we've got this side done, we're gonna do the exact same thing on the other side. Everything is pretty much the exact same except for the other side of the trailer has a yellow wire in our loom there. So now, as we said earlier, we needed to make some tie off points here for our running lights. So that's what we're gonna do now since we've wired everything up to the taillights. We're just gonna install our little clearance lights here. So this could vary depending on your particular setup, but usually there's gonna be a hole for your wires and then two holes for the mounting tabs there. So we're just gonna fish our wires down through there. Try to fish them out to the bottom as best we can. So now we're gonna go ahead and just secure our light using self-tapping screws. Again, this could vary depending on which actual clearance light you have, but most of them are fairly standard in regards to this two-hole design. And then once you have your light mounted and your wires ran down through here, you'll just crimp them and then secure them with electrical tape like you would normally. So now we're gonna go ahead and test everything out to make sure everything was done correctly. Now we have a tester box specifically for this but you guys are just gonna hook up to your vehicle there. Nice and simple. Gonna go ahead and turn on the taillights. We should see both the marker lights illuminated as well as the taillights at the rear. So we'll check both sides, make sure that's good. And then we will turn on our left turn signal. Perfect. Now we're gonna switch over to our brake lights. So the brake lights should illuminate the taillights on either side there. And then finally, we'll have our right turn signal. Make sure the right turn signal was illuminating there on that side as well. So looks like everything's working correctly for us. If you guys don't have any luck, just make sure to check all your connections with your butt connectors. That's usually the number one fail point and also check your grounds as well. So overall it's pretty easy. So you guys really shouldn't have any issues but just a few pointers there if your lights aren't working. So with all of our wires working correctly, that's gonna do it today for our look and installation of the Wishbone 4-way 25 foot trailer wiring harness..
Average Customer Rating: 4.7 out of 5 stars (107 Customer Reviews)
4-Way trailer harness connects to your tow vehicle to control trailer light functions. Wishbone-style harness comes with 2 tail light wires split for simple wiring.I had a hard time finding a 6 wire to a 4 way plug this is what my trailer had so I wanted to replace it with what it had originally could of used the 5 wire to 4 way plug but wanted to replace what it had so thank you for carrying it and for the nice prompt delivery
I just wish is was a more durable gauge wire. Also, the copper wire is NOT tinned so it won’t hold up as well in a salt water environment. Not a bad product but don’t use it for a boat trailer on the coast.
This is perfect for tilt trailers and others with bad grounds through the hitch to the taillamps.
Your site was very easy to navigate. Products were well explained. Everything I ordered came in 3 days with no problems.Tracking number was sent as soon as processed. I will buy from them again.
Glad somebody makes this type of harness with full-length ground wires on each side of the trailer. Wire guage is about 18 according to my Klein strippers. It appears to be copper. The plug lists Taiwan as country of origin. I'm happy with the product for the price. With a careful, proper installation, this should provide trouble-free service for many years. I gave 4 stars. With a more substantial plug-to-wire attachment, I would give 5.
Nothing like leaving town at dusk only to find out at the first rest stop that your trailer lights are intermittently working. Ive used etrailer wiring harnesses in the past which surpassed the original harness. Buy with confidence.
Used this to install lights on a curt folding cargo carrier, was good to have 2 ground wires(white) and 2 parking light wires(brown), to avoid extra connectors that would cause corrosion problems
I purchased this wiring harness to replace one for my cousin on her trailer. Everything was as it should have been..the install job was much easiernot having to battle the harness as well as the old trailer. One year later and everything is still A Ok.
works great just what i want. everything i have every ordered fom etrailer has been on the spot. can't ask for anything more
Easy way to kep left and right straightened out.
A year after purchase and installation, the wiring harness and submersible LED taillights are functioning as expected. I am very pleased with the product and service etrailer provided.
The wiring harness design is fantastic, and I was able to re-wire easily. The only negative is that the wire is this - I believe 18 gauge. If I had a choice, I would have preferred 16 gauge wire - 14 gauge would have been kick-butt, but perhaps overkill. Anyway, I've got new LED lights working great off of new wiring! Yeah!!
Good product with great customer service! Always go out of their way to make online buying a good experience.
I paired this with new LED lights for my boat trailer, what an upgrade from what came with it.
Product works well for my application
So easy to find what you need, and pricing is always reasonable. First stop for all my towing and trailer needs.
This makes wiring tail lights so much easier. I always had to run the white ground wire to each light separately on my trailers. I had a few tilt boat trailers that wouldn't always ground the lights through the rusty tilt bolts. This harness makes the process easier, going to order another one soon.
Overall quality is very good. Product was just as described. Prompt shipping. The only thing that would have made it better is having tinned copper instead of bare copper wire. But that should not be an issue if waterproof heat shrink tubing (adhesive inside) is used for the connections.
My trailer light problems finally solved the separate grounds are a great idea.
Did not come in separate bundles like the picture. But still easy to work with and a good product.
Good product that's hard to find. No more grouding to trailer!
works good! In my experience, the full length ground is well worth it.
Very nice Trailer light wire harness! It has 2 separate full length grounds to run all the way to the left and right tail lights. That assures you a perfect ground all the time as you are no longer relying on grounding through a screw into the frame and through the frame to another screw at the tail light. You now have a direct ground wire from your vehicle to the trailer lights! Speedy shipping! You will not find this type of harness anywhere else.
I paid $[XX] (plus shipping) more than what I could have purchased this wiring harness local. The gauge (16) vs (14) on this wire is smaller wire (hope that is not an issue in the future). What caught my attention was the dual ground (that's a plus) ;however, there are no circle connectors or self-tapping screws to secure the ground(s).
Just what I needed to get my work done
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