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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.
On this flat bed trailer, we're going to install part number A20WB. This is a 20 foot, wishbone, 4-way trailer wiring harness. First, we'll go ahead and take our wire harness apart. We'll go ahead and untangle it and get it straightened out. We'll also point out the feature of a wishbone, where you have left and a right-hand side. You notice there's a green wire with a brown wire and a yellow wire with a brown wire. That carries a running light circuit to both sides.
Our yellow will go to our left side and our green will go to our right side. Now, on this particular trailer, we're going to run our wires through a tongue and we're going to go ahead and drill out a hole behind the coupler. We'll go ahead and drill a nice 16th hole. Then, install snap bushing. The part number we're using is SWC8055. Once we have our bushing installed, we'll go ahead and use a pull wire to pull our new wire harness into place. Now, we're actually using an old piece of airline tubing.
This could be any piece of wire if it can help hold its shape and still maneuver it through the tongue of a trailer. We'll go ahead and running it out to the end of a tongue of a trailer underneath. We'll go ahead and attach our wire harness to our pull wire using some electrical tape. We'll take the two lengths of wire and put one behind each other to keep it as narrow as possible and fit through the bushing. Once we have the wire secure, we'll go ahead and pull it through the tongue and out the back. Then, we'll go ahead and take up all our slack. Then next, we'll go ahead and work with our ground wire. Now, in this case we don't have a fastener that'll work with a large ring terminal on it, so we're actually going to change out the ring terminal to a smaller one.
Now, the ring terminal we're using is part number 44-5356A and we'll use a self-tapping screw. The screw we're using, uses a 3/8 nut driver on it and it's about a number 14 size screw. We got ground wire attached. Then, we'll go ahead and use some loom material. We'll be using part number 459075-1. We'll just go ahead and use that to cover up the wire, going from a 4-pull to where it goes into the tongue.
Just under 3 foot will work just fine. Maybe some electrical tape to seal up the ends. Now, push your wire into place and then secure it at the end, so it doesn't get pulled out at the bushing, we'll use a limb clamp. The limb clap we're using is part number A0500. Next, we'll go ahead and make a quick inspection on where the wires came out the tongue, to make sure we don't get pinched. In this case, we actually use a couple small quarter inch holes on each side of a tongue, to route our wires through, to keep it away from the bolt on the inside and sometimes, where a tongue is bolted to a trailer frame, it'll work like a scissor. It's a good idea to just move the wires out of the way. Working on our passenger side, we'll go ahead and route our wires along the frame components and out to our first running light. We'll also zip tie it along the way as necessary. We'll go ahead and run our wire harness to a light and there's a length of wire on it. We'll go ahead and match up to the length and mark it. Then, we'll split our wires in half to get access to the brown wire. We'll go ahead and cut our brown wire in half. We're going to use a buck connector as a junction to connect three wires together. Nail 00:03:33 One end of the buck connector, we'll take our black wire from the light and connect that to the brown wire from our harness. Then on the other end, we'll get the rest of the brown wire, going into the buck connector. The buck connector we're using in this application is part number DW05744-5. We're using a heat gun and it makes it easy to point the heat in a direction that you want. You can also use a lighter or a barbecue pit lighter, as well. Then, optionally we can go ahead and add some electrical tape to keep the bundle together. We'll use another limb clamp, the same part number, and we'll go ahead and use that to hold the wires underneath the trailer. We'll go ahead and continue running our wire out to our tail light. We'll go ahead and run it through a frame and any pre-existing mounts for the old wire. Once we get to our tail light, we'll go ahead and remove any pre-existing wires going into a tail light. Once we have our wires ran to our tail light, we'll go ahead and cut off our excess . and strip back the wires about a half an inch. Now, on our passenger's side, our wires going to be using the brown wire, of course, for running light circuit and then the green wire for left-turn signal and break signal. Now, on this particular light, the wires just push into the light itself. There's a little tab in there that grips the wire. When we're done with our passenger's side, we'll go ahead and do the same exact steps over on the driver's side. However, on the driver's side, we'll use a brown and yellow wire. That'll do it for part number A20WB. 20 foot wishbone, 4-way trailer wiring harness on this old flat bed trailer. .
Average Customer Rating: 4.9 out of 5 stars (240 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.It's a simple item but try to find it somewhere else as a stand alone product. I've used etrailer before with great results and this was no exception. Let's be honest, if you've been to the site once, you're coming back! I have a 5 x 12 utility trailer that has good lights but the wiring was a disaster. The harness connector had been patched and there were at least 5 splices throughout the lines. It was nice to lay out the new harness, make the light connections, tack everything up and out of harms way (there's an idea) and my lights work like new. I like the ground fastens under the jack bolt. Saves drilling a screw in (see the baby hole?) Good to feel safe on the road again. As easy and inexpensive as it was, I don't know why I waited so long.
Rewired the trailer relatively easily. Had a ground problem that was easily fixed. My only problem was the VERY long shipping. There is no excuse.
William E - 07/23/2021
Some men, when they arrive at sixty five or above, run out and buy a fancy red sports car. I bought an old trailer that looked good and sturdy. It was very inexpensive. It needed some welding and rewiring. Luckily I have a neighbor who is an excellent welder, and the wiring was easy to find on the web and easy to install. I have gotten great pleasure using my trailer. I even thought about painting it red, but then that would look ridiculous.
After trying to spice wires with other kits I found ETRAILER made a order got in just a couple days and had it wired hassle free this is a great product and I even order another one for my boat trailer and a easy plug kit for my jeep!! Will continue to use ETRAILER in the future!!
Overall the wiring harness was satisfactory. Would recommend adding more length to the ground wire. In addition, addition of several splicing connectors (to run wires to the side lights and connect the tail lights) would be beneficial. Finally, a dust cap for the four prong connector would be an improvement. All that being said, the product installed quite easily.
Just wanted to let you know that the Optronics Miro-Flex Trailer Lights are working great!! Much brighter and more visible that the basic lights I replaced! Hope your business is doing well through this Covid crisis!! Thanks for the communication.
This harness worked great for installing tail/brake lights on the back of my bike rack.
Just rewired a cargo trailer I bought that the lights were always going out. Found 20 butt connectors the guy used no wonder they worked off & on. Now with two new tail lights & new wiring with a straight connection everything works like it should. Everything I have bought from etrailer has been good quality & fast shipping. Thanks
This harness worked great. I liked their website,easy to use and easy to order. Shipping was fast. Pleased with this purchase. Thank you
Easy replacement. I replaced my vehicle harness so why not just run all new! Thanks etrailer!!!
This a great wire upgrade for the original on my trailer! If you are in the need to rewire your trailer I recommend this item.
Fantastic !!!! Great product, exactly as detailed, exactly as pictured, easy ordering, and on time shipment / arrival. I have never wired a trailer before, but after watching the online video program and following the steps I was able to complete the project in a hour for a 14' boat trailer. Prior to ordering, I did a lot of price comparisons in my area and I could not beat etrailer pricing. Great product.
Martin F - 10/19/2015I needed every inch for my 12' trailer.
Simple and quality wire harness set Needed to rewire a friends trailer w/ an updated set up Easy to use and install for this type of set up
Mark v - 11/25/2015Exactly what I needed to begin rewiring a trailer. My sons cattle ate the trailer plug and pulled out the wiring in the tongue.
JOHN M - 07/31/2019Works great,
Kenneth - 08/05/2019I am driving safer because I can now hang brake lights on bikes on my hitch-mounted rack. Easy to do with what etrailer sent me. Super helpful on-line.
This is more of a review for etrailer.com than the product; although the wiring harness worked perfectly. The service etrailer.com provided was excellent from start to finish. I highly recommend them!
Great transaction as usual with Etrailer. Shipping and communication is great each and every time.
speedy service and delivery, great telephone reps, and great product! LED lights work great and easy to install. Highly recommended
What do y'all want a follow up to? If i had a nickel for every item I've ordered off of ETrailer, I wouldn't have to work for a few months... I keep coming back because the prices are fair, shipping is free and fast, and ETrailer has everything I need. I do wish you sold trailer kits though. Being a welder, I have built a few trailers in my free time and sold them for a small side business. Why isn't there an axle, fender, brakes, springs (shackles and all hardware) tires and wheels kit? It would be nice to not have to go and click and add to cart all the multitude of items I need to build a trailer individually. Just saying...
Harness was purchased to rewire my Shoreland'r boat trailer. It came very well packaged. The internal wire was strong and did not fray when stripping off the sheath. The main thing I liked was that the right and left (gr/br & yel/br) wires were separated all the way to the connector. The shipping fees were very reasonable. I would recommend this product all day. THANKS etrailer.com. Now if I could just figure out why I keep blowing my running lite fuse in my truck???
Heather A - 09/26/2017Worked great! Thanks.
very good quality. arrived on time.
Works as stated
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