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20 Ft 4-Way Trailer Wiring Harness - Wishbone Style - 30" Ground

20 Ft 4-Way Trailer Wiring Harness - Wishbone Style - 30" Ground

Item # A20WB
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A20WB - Trailer End Connector Optronics Trailer Wiring
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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. Lowest Prices for the best trailer wiring from Optronics. 20 Ft 4-Way Trailer Wiring Harness - Wishbone Style - 30" Ground part number A20WB can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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Optronics Trailer Wiring - A20WB

  • Trailer Connectors
  • Trailer End Connector
  • 4 Flat
  • Plug and Lead
  • 11 - 20 Feet Long
  • Optronics

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.


Features:

  • 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
    • Allows you to run wires separately down each side of the trailer to tail lights without needing a jumper wire
  • Color coded wires help with installation
    • White - ground
    • Brown - tail lights
    • Yellow - driver side stop/turn
    • Green - passenger side stop/turn


Specs:

  • Wire harness length: 20'
  • Ground wire length: 30"
  • Wire gauge: 20 AWG


A20WB Optronics 20 ft. Wishbone 4-Way Trailer Wiring Harness with 30" Ground Wire




California residents: click here


Video of 20 Ft 4-Way Trailer Wiring Harness - Wishbone Style - 30" Ground

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.




Video Transcript for Optronics Wishbone Trailer Wiring Harness Installation

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. .


Customer Reviews

20 Ft 4-Way Trailer Wiring Harness - Wishbone Style - 30" Ground - A20WB

Average Customer Rating:  4.9 out of 5 stars   (256 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.

by:

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.


Comments
Very good. Product has held up nicely
Jonathan - 05/26/2022

by:

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.


Comments
Outstanding
Michael I - 04/24/2022

by:

Cheap--wired it in to my Chevy and tried to separate the male connector from the female and the rubber sleeve separated from the terminals on the make connector. Threw the GARBAGE into the garbage and re-installed my old one. Do not buy this cheap junk. Wish I would have taken a photo.



by:

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.



by:

very good to have trailer parking light wires in a wishbone configuration



by:

Comes with two brown leads making it dead simple to install. Just lay it all out and install it. Seems to be of good quality too. Nice wire gauge.


Comments
That complete rewire is still working fine after a year. Very satisfied.
Bryan - 11/03/2021

by:

product worked great price was ok easy to follow directions



by:

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



by:

I have been very pleased with the quality of the product and that it is very durable and works great . The wire seems to be holding up well



by:

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.


Comments
As advertised . Shipping was slow
William E - 07/23/2021

by:

Always get great products and service from etrailer



by:

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!!



by:

Excellent service as always and great prices on quality parts



by:

Very good product, arrived on time and worked as planned



by:

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.



by:

Product was as advertised. Great materials. Would highly recommend.



by:

This harness worked great for installing tail/brake lights on the back of my bike rack.



by:

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


Comments
Just fine still working correctly
Mark v - 11/25/2015


by:

Works great,


Comments
Still working good
Kenneth - 08/05/2019


by:

Nice- heavy duty plug. Well made, and ready to install. Just as described. billooltewah



by:

This harness worked great. I liked their website,easy to use and easy to order. Shipping was fast. Pleased with this purchase. Thank you



by:

Quick and easy



by:

just what i needed



by:

Easy replacement. I replaced my vehicle harness so why not just run all new! Thanks etrailer!!!



by:

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.


Comments
Thanks for the follow up - One year later the products are working spectacular and I keep plugging away at your company - telling all of my friends about it.
Martin F - 10/19/2015

25
256
Show More Reviews

Ask the Experts about this Optronics Trailer Wiring



  • What Gauge Wire is Used in the Wishbone 4-Way Trailer Wiring Harness, # A20WB
    I spoke with my contact at Optronics about the Wishbone 4-Way Trailer Wiring Harness, # A20WB. They had documentation stating the green wire is 19 gauge and the yellow wire is 20 gauge. She could not state for sure what gauge the white and brown wires are but either 19 or 20.
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  • No Brake Lights or Turn Signals on Trailer With a 4-Way Connector With 5 Wires
    You will first want to make sure the 5 wires on the trailer plug is wired properly to the trailer. The white wire is for ground, the green wire for right turn and brake, yellow wire for left turn and brake, green with brown wire is for right side running lights, yellow with brown wire is for left side running lights. If the wiring is all correct then you will need to check the trailer connector on the truck and trailer for a ground connection issue, or a short on the tail light circuit...
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  • Should Boat Trailer Lights Short Out When Backed Into Water
    Water and electricity don't mix well. The best recommendation I can make for you would be to unplug your trailer wiring before you back your boat trailer down the ramp and then don't plug the lights back in until the trailer has dried out thoroughly. While the trailer lights themselves can be listed as waterproof or submergible the wiring of the trailer isn't always so that is why unplugging the trailer lights is recommended. If the assemblies were ever replaced water can easily get in...
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  • Troubleshooting Trailer Lights That Stopped Working After Bulb Replacement
    There is no difference between the red and amber colored trailer lights. They are the same lights with a different color lens on them. If all of the lights on your trailer went out I would suspect you blew a fuse somehow in the process of replacing the light. I would check the fuse box of the vehicle you connected this trailer to looking for the trailer wiring fuses and replace as necessary. I attached an FAQ on trailer wiring as well as troubleshooting 4-way installs that should be helpful...
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  • Replacement Wishbone 4-Way Recommendation for a Trailer
    You are correct. Based on the wire colors that you listed you would want a wishbone 4-way like the part # A20WB. The colors of this 4-way would match up exactly to what you have listed with the only addition being the white wire of the new 4-way running to a clean metal surface on your trailer. The brown wires of the 4-way will be run to the yellow/brown and the green/brown wires. It doesn't matter which one as it's the same circuit (running lights). I attached an install video for...
    view full answer...
  • Can 4-Way with 4 Wires be Used with 4-Way with 5 Wires
    Yes, the 4-ways with 4 wires and the ones with 5 wire perform the exact same functions so they both can easily be used together. What you have a picture of is a wishbone 4-way that has the two running light circuits on it. One for either side of the trailer. That's why it has 5 wires. The 4-wire 4-ways use a single wire for this circuit but you then have to split it off to either side of the trailer. The two wires in your picture that have brown on them are that circuit. # A20WB is an...
    view full answer...
    Image 1 for
  • Recommended 4 Flat Wishbone Harness for Trailer
    The shortest 4-Way wishbone harness we currently have available is the 20 foot Optronics Wishbone 4-Way Trailer Wiring Harness # A20WB. This is a split wishbone 4-way trailer wiring harness that features the two brown tail light wires that you referenced. All the wires are 20-AWG gauge. Since the harness is a bit longer than you are needing, I recommend simply taping up any excess wire once the connector is installed. I have attached a couple short video demonstrations on this harness...
    view full answer...
  • Recommended 6 Foot Long Wishbone Wiring Harness for Boat Trailer
    The shortest wishbone 4-Way trailer wiring harness we have available is the Optronics Wishbone Harness # A20WB. This wishbone harness, which has the 4-flat connector with 5 wires, features 20 feet of wiring length. Since this is a bit longer than what you are needing, you can simply tie off any excess once you have everything installed. All the wires are 20-AWG gauge. I have also attached a couple video demonstrations on this product that you can check out.
    view full answer...
  • How to Wire Up New 4-Way to Trailer When Wire Color Functions are Unknown
    It's interesting that your trailer connector has two green wires but aside from that standard wire colors. Typically white is ground, brown is running lights (where you would normally see 2 wires of same color), yellow is left turn/stop, and green is right turn/stop. You might try putting 12 volts via a car battery on both of the green wires to see what they illuminate. You may even try this for all of the color wires minus the white to make sure you have the functions determined. For...
    view full answer...
  • What Color Are the Brake Lights On A 4-Way Flat Plug Of Wishbone Wiring Harness?
    The brake signal is run along with the blinker on separate wires. The passenger side is normally green and carries the right turn and brake light. The driver's side is normally yellow and carries the left turn signal and brake. The remaining functions are running/tail lights on the brown wire and the ground which is the white wire. I've attached an article to assist. A wishbone harness like # A20WB will give you two brown wires so you don't need to run a jump wire from one side of...
    view full answer...
  • What is the Wire Material Made of on the
    I went out to our warehouse and pulled the wiring harness. The wire in the Optronics Wishbone 4-way Trailer Harness, # A20WB, is copper.
    view full answer...
  • Will 20 ft. Wishbone 4-Way Trailer Wiring Harness # A20WB work with LED Trailer Taillights
    Yes, the 20 ft. 4-Way plus Wiring part # A20WB that you referenced will work great with LED trailer lights. There's no reason that it wouldn't work. This is a wishbone wiring kit for the running light circuit which means that the running light circuit has a wire for each side of the trailer. That's why there are two brown wires. I attached an install video for this kit for you to check out as well.
    view full answer...
  • How Does Wishbone 4-Way Wire to Trailer's 4-Way Wiring that has 7 Wires
    The two white wires are the ground circuit which would run to the white wire of the # A20WB, the black wire has to be the right turn/stop signal although that color is typically solid green. The brown is a running light circuit that runs to clearance lights on the trailer, the yellow brown runs to the taillight assembly for the running light circuit, and green brown is the left turn/stop circuit. All of these run to either of the brown wires of the 4-way, and then the yellow is the left...
    view full answer...
  • Wire Gauge for the Wishbone 4-Way Trailer Wiring Harness, # A20WB
    I spoke with my contact at Optronics about the Wishbone 4-Way Trailer Wiring Harness, # A20WB. They had documentation stating the green wire is 19 gauge and the yellow wire is 20 gauge. She could not state for sure what gauge the white and brown wires are but either 19 or 20.
    view full answer...
  • Wire Color for Each Function on 4-Way Trailer Wiring
    You likely saw it on our wiring help article which I linked. The traditional wire coloring of a standard 4-way like # A20WB is both browns to your running lights, one per side of the trailer, green to your right turn and brake light, yellow to the left turn and brake light, and the white is the ground wire.
    view full answer...
  • Trailer Lights Function Differently on Two Different Vehicles
    If you have different lighting issues with the trailer depending on which vehicle you are using then that leads me to believe there is an issue on the vehicle. I recommend you check the trailer lighting circuit fuses on each tow vehicle to make sure all is in order. Also, I recommend you run a ground jumper wire for each light up to the main trailer connector ground as well temporarily to see if that fixes your issue. If you want to check the trailer on its own then you can do so with the...
    view full answer...
  • Wire Gauge and Ground Locations for LED Running Lights on a Trailer
    Since LED lights do not require a lot of amperage you can go with relatively small wire. Using 16 or 18 gauge wire will be fine. Harness # A20WB uses 20 gauge wire which is on the small side but certainly not a problem at all for LED lights even incandescent lights on a trailer. We have various types of 16 and 18 gauge wires, see links, depending on the configuration needed. Also many of the options are sold by the foot so you would change the quantity amount to reflect how many feet you...
    view full answer...
  • Troubleshooting Trailer Stop/Turn Circuit Not Active for 2011 Jeep Grand Cherokee
    It should be a fuse that is called trailer wiring right stop/turn circuit in the fuse box. It could also be cut wire up stream of the connector as well. I pulled up the owners manual for your 2011 Jeep Grand Cherokee and the only trailer towing fuse listed is in the J14 lamps and it looks like it covers all the circuits. That makes me think that your problem is actually on the wiring of the connector and not on the vehicle.
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  • Does Optronics A20WB Trailer Wiring Harness Use All-Copper Wire
    The Optronics 20 foot 4-way trailer wiring harness, part # A20WB is constructed of 18 gauge stranded all-copper wire. I've confirmed this with my Optronics representative.
    view full answer...
  • Why Would Trailer Wiring have Two White and Brown Wires
    It's not uncommon for trailer wiring to have more than one wire for the same circuit for the ground and running light circuit. For the running light circuit (brown wire) this is to allow you an easier way to run the circuit to either side of the trailer. For the ground circuit (white wire) it's to allow for making more ground circuit connections easier since all of the circuits have to be grounded. So if your trailer has two ground wires you could run them both together and then to the...
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  • Trailer Lights Stop Working When Headlights are Turned On with a 2007 Chevrolet Avalanche
    The most likely cause of your problem is a bad ground connection. It has enough of a connection that it works in the day time because you have less current draw on those circuits with the head lights off. As soon as the headlights are on, you are pulling more current than the weak ground can support. Check the ground connections on the trailer wiring. Make sure you have good metal to metal contact. Paint and corrosion can act as insulators so make sure the grounds are touching clean metal....
    view full answer...
  • Trailer Running Lights Work with a Chevy Truck But Not with 3 Different Ford Trucks
    Unless someone wired in the trailer connectors on the trucks and they are not factory or plug and play types of harnesses then they could be wired differently. But otherwise Ford and Chevy trailer connectors will be the same. It is possible that there is a ground issue that the Chevy harness does not have a problem with but the Ford wiring does not like. To determine if the issue is on the truck or trailer side you can use a circuit tester like # 40376 if you do not already have one and...
    view full answer...
  • Green and Yellow Wires on Trailer Wiring Harness do Not Show Any Power
    There are any number of reasons that you are not getting power on the green and yellow wires. If this is on the trailer side, the first step would be to test the vehicle end 4-Way trailer connector to see if power is at least getting to that point. Use a circuit tester like # 40376 if needed to test the 4-Way end on the vehicle. If the power is not getting to the 4-Way that means the problem is on the vehicle side. I would need to know the year, make, and model of the vehicle and if the...
    view full answer...
  • 4-way Wiring Recommendation for a Wishbone Wired Boat Trailer
    What you have is a wishbone 4-way that seems to have a few circuits run to the ground circuit (the jacketed circuit that has the 2 white wires plus the green wire with the white tracer). What you could use would be a 20 ft. Wishbone 4-Way Trailer Wiring Harness # A20WB. This has the wishboned running light circuit. Aside from that you would need to run all the wires to the ground circuit of the # A20WB. Basically you will need to run the wires all together from each circuit of your boat...
    view full answer...
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