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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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Optronics Trailer Connectors - A20WB
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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 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 800-298-8924 for expert service.
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Optronics Wiring - A20WB

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

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




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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 Wiring - Trailer Connectors - A20WB Review

Today we'll be reviewing part number A20WB. This is Optronics 20 foot wishbone 4-way trailer wiring harness with a 30 inch ground. It's going to feature a 4-way flat connector. Wires come straight from that and they immediately split all the way to the very end. Again, you're going to have 20 feet in total length. Then you're going to have that 30 inch ground wire.

This harness will work as an exact replacement for truck light number 108820. That's going to do it for our review of part number A20WB. This is Optronics 20 foot wishbone 4-way trailer wiring harness. .


Customer Reviews

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

Average Customer Rating:  4.9 out of 5 stars   (209 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.

- A20WB
by:

Perfect for the 10 foot long trailers I build. Really like the 30 inch ground lead. 735529



- A20WB
by:

Order was easy and package arrived within a week. Product was as advertised. 668067



- A20WB
by:

GREAT, needed something long and no spices this worked out great 677782



- A20WB
by:

I have ordered many items from e-trailer, always prompt deliveries 603790



- A20WB
by:

Works great, 550230


Comments
Still working good
Kenneth - 08/05/2019

58658

- A20WB
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. 539599



- A20WB
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 715875



- A20WB
by:

As promised and good install instructio ns. 867281



- A20WB
by:

Always efficient - easy ordering proces s! 860803



- A20WB
by:

Good quality easy to install very satis fied. 854881



- A20WB
by:

the service was fast and correct will be installing the harness tomorrow and it was as described Thank you for your service 853438



- A20WB
by:

On my trailer 852499



- A20WB
by:

Have used this harness several times. 848930



- A20WB
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. 848598



- A20WB
by:

Perfect 848011



- A20WB
by:

Great transaction as usual with Etrailer. Shipping and communication is great each and every time. 830361



- A20WB
by:

Great lights and excellent wiring. Went on my trailer very easily. 820605



- A20WB
by:

I haven't used it yet but it looks to be of great quality. fast shiping 815191



- A20WB
by:

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! 814435



- A20WB
by:

Good quality replacement for my trailer. 797728



- A20WB
by:

Took me less than two hours to rewire my trailer. Would have been sooner if I didn't have trouble removing the old wiring. The quality of the wire was better than expected. 796269



- A20WB
by:

Used as spare wire for a hitch project. Good stranded wire. 792425



- A20WB
by:

Length was just right. 785375



- A20WB
by:

Great instructions both written and on video, easy to install and works like a charm! 779113



- A20WB
by:

Better quality than what it replaced. Plug has grips moulded in to make it easier to unplug and plug in. 776696


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Ask the Experts about this Optronics Wiring

  • Trailer Wiring Using Wishbone or Y-Harness 4-Way Trailer Connector
    The 20 Ft 4-Way Trailer Wiring Harness - Wishbone Style - 30" Ground # A20WB simply has two wires that connect to the running light pin of the 4-way. There isn't a 5 wire we carry in spools or by the foot, but we do carry the Bonded 4 Wire - per foot # 16-4B-1 and then you can add Primary Wire - 16-Gauge - White - per Foot # DW02359-1 for the additional running light wire. You can connect these to a 4-way flat connector using the Hopkins Endurance Quick-Fix Replacement 4-Way Flat Trailer...
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  • 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.
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  • 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...
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  • 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.
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  • 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.
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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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  • Rewiring and Installing New Tail Lights, Wiring, and Trailer Connector on a Trailer
    It looks like you have the lights and grommets, wiring harnesses, hardware, reflector, wire loom and butt connectors. But the butt connectors will be too large for the wiring harness. You will need 22 to 18 gauge 5-pack # 05730-5. The wiring on the wishbone harness is 19 to 20 gauge. You may also want to invest in some dielectric grease # 11755 to keep moisture and corrosion out of the electrical connections. And if your trailer has any clearance lights, those are missing for the...
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  • 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...
    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...
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  • Recommended Replacement 4-Pole Wishbone Trailer Wiring Harness
    It sounds like your trailer has a special type of 4-pole connector called a wishbone harness, such as 20-foot # A20WB or 35-foot # A35W42B. These wishbone harnesses simply use two brown running light wires to make it easier to wire your trailer's lights. The dual wires mean there is no need to run a jumper wire from one side of the trailer to the other; one wire runs down each side of the trailer frame. You can use butt connectors like # 05731-5 which you can wrap in electrical tape...
    view full answer...
  • Installing a 4-Pole Flat Harness and the 5-Wire Wishbone Harness
    Sounds like your trailer has a wishbone wiring harness, like # A20WB. This harness uses two brown running light wires to allow you to wire the trailer running lights without running a jumper wire from one side of the trailer to the other. If you need to wire a 4-pole on the trailer side, then all you will have to do is at the splice two brown wires together. Then use only one of the brown wires at the trailer plug.You can use # 05731-5 butt connectors to splice the two brown wires and...
    view full answer...
  • Right Side Brake Lights and Turn Signal Do Not Work on the Trailer
    It sounds like your problem may be limited to just one circuit - the wire that carries the right turn signal and brake light. To begin testing, I recommend checking the vehicle side and trailer side connectors for any signs of corrosion or damage and repair as needed. If the connectors look fine, I would test the vehicle side trailer connector with a circuit tester, like part # 40376, to make sure the vehicle is sending power to the trailer (see video). I would test each pin as a helper...
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  • 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...
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  • Troubleshooting Reasons Why Boat Trailer Running Lights Are Not Working
    There are many possible reasons why the running lights are not working on your boat trailer. First, I recommend checking the ground connections. Trailer lights usually ground through the mounting studs. They will need to be attached to a clean and corrosion free bare metal surface. If you recently added a plastic license plate cover, that could also be causing the problem. You will also want to make sure that the main ground from the trailer connector is attached to a clean and corrosion...
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  • Installation of Trailer Wiring Harness Through Frame or Conduit on 6x12 Trailer
    It sounds like your current wiring is run through either conduit or the frame of the trailer. If this is the case, then I recommend utilizing the current wiring as a pull wire to bring the new wiring into place. You can simply use electrical tape like # DW04367 to connect the new wires to the old wires with a tight wrap to give you the connection to pull the old wire from tail light end allowing the new wire to pull from the coupler end through the metal tube into position. I recommend...
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  • Trailer Lights Go Out When Brakes are Applied
    It sounds like you do have a ground problem. You might want to check where your lights are mounted. If they are bolted on there could be some corrosion between the mounting bracket and the trailer or the bracket and the light. If this is the case you will have to clean out any corrosion you find. We have a wire brush Battery Post and Terminal Cleaner - Wire Brush # DW00254 that could be used in the cleaning process. There may be a ground loss if there is a plastic license plate bracket...
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  • Recommended Trailer Wiring Replacement For Sea Doo Trailer
    With two brown wires in your photo it indicates a wishbone harness basically allowing running lights to be sent to each side from the coupler location instead of using a jump wire from one side to the other. This is very common to use with boat and personal watercraft trailers. It looks like the end of the connection has where the dog chewed the wires and if so, you can simply use the Hopkins Endurance Quick-Fix Replacement 4-Way Flat Trailer Connector w LED Test Lights - Trailer...
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  • No Drill Mounting Bracket and 4-Way Trailer Wiring Harness for a 2009 Dodge Grand Caravan
    The Correct Trailer Wiring Harness for the 2009 Dodge Grand Caravan is the T-One Vehicle Wiring Harness with 4 Pole Trailer Connector, item # 118552. The 2009 Dodge Grand Caravan wiring requires a powered converter to protect the vehicles sensitive wiring and circuitry. We have a video and instructions online, see links, for installation help with this harness. For a bracket to hold the trailer connector at the hitch two items are needed. First the Short No-Drill Mount Bracket, item...
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  • 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...
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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...
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  • Troubleshooting No Trailer Brake Light or Turn Signal on Left Side
    Since you have tested your 2012 Ford F-250 with a multimeter like # BTMT15, you most likely have an issue with your trailer ground connection. Some vehicles using the same trailer may not have issue as the voltage sent may be ever so slightly different. The place to start now is checking that left side tail light assembly. You will have a ground connection whether using a separate wire or in the mounting hardware itself which is often used for a ground. Make sure that ground is bare...
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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...
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  • 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.
    view full answer...
  • Butt Connectors for 20 ft. Wishbone 4-Way Trailer Wiring Harness with 30" Ground Wire
    For the wishbone trailer wiring harness # A20WB you can use butt connectors # 05730-5 which fit 22 to 18 gauge wire. This is a 5-pack. The wire gauge for the wishbone harness is 19 to 20 gauge.
    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...
  • How To Replace 4-Way Trailer Connector with 5 Wires with One That Has 4 Wires
    In order to replace a trailer side 4-way connector that has five wires like the 20 Ft 4-Way Trailer Wiring Harness part # A20WB with a trailer side 4-way connector that has four slots/wires like the Quick Fix 4 Pole Flat Trailer End part # HMC20031 you'd simply need to combine the two brown wires as they are running lights for each side of the trailer. In regards to the trailer lighting issue, you likely have some sort of short on the green wire or a loose connection.
    view full answer...
  • Troubleshooting Trailer Lights Where All Functions Don't Work or Are Dim
    Tail lights do have individual ground connections. This is often through the mounting hardware instead of having a separate ground wire. With a weak ground connection you may still get some function on the light without all functions working. I recommend cleaning the mounting locations to make sure you have a bare metal to metal connection. If that doesn't solve your issue I recommend tracing your wires using a circuit tester like # PTW2993 to see if there is a short which I wouldn't...
    view full answer...
  • 4-Pole to 5-Pole Trailer Wiring Adapter
    If you need a 4-pole to 5-pole wiring adapter we have several including part # 20036; this and the other similar items are shown on the linked page. These adapters allow adding an additional circuit to a 4-pole. If you need a different item please send along a photo to show us exactly what you have and what you need to replace. I also included a link to our main page for all types of wiring adapters.
    view full answer...
  • 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.
    view full answer...
  • 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...

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Info for this part was:

Expert Research:
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Patrick B
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Michael H
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Jeff D
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Jameson C
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John H
Expert Research:
Adam R
Installed by:
Cole B
Updated by:
Sarah W
Updated by:
Brian T

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