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35 Ft 4-Way Trailer Wiring Harness - Wishbone Style - 42" Ground

35 Ft 4-Way Trailer Wiring Harness - Wishbone Style - 42" Ground

Item # A35W42B
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Optronics Wiring - A35W42B
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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. 35 Ft 4-Way Trailer Wiring Harness - Wishbone Style - 42" Ground part number A35W42B can be ordered online at etrailer.com or call 800-298-8924 for expert service.
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Optronics Wiring - A35W42B

  • Trailer Connectors
  • Trailer End Connector
  • 4 Flat
  • Plug and Lead
  • Optronics
  • 31 Feet and Longer

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: 35'
  • Ground wire length: 42'
  • 3-Year Warranty


Manufacturer Cross Reference
Harness will work as an exact replacement for:

  • Truck Lite # 108835


A35W42B Optronics 35 ft. Wishbone 4-Way Trailer Wiring Harness with 42" Ground Wire

Alternate part number: A-35W42B




California residents: click here



Customer Reviews

35 Ft 4-Way Trailer Wiring Harness - Wishbone Style - 42" Ground - A35W42B

Average Customer Rating:  4.9 out of 5 stars   (462 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.

- A35W42B
by:

Fast service and the product was just what I needed. Highly recommend this company and will buy from then again. 738470



- A35W42B
by:

Awesome products and superb service thank you 734208



- A35W42B
by:

Worth it's weight in gold when it came to wiring my trailer. I bought this for a homebuilt camper project and this made wiring my lighting simple. Although, my only complaint would be the short 42" ground wire. I'm a firm believer in not using the trailer frame for grounding - I consider it a sloppy installation practice. I'd rather run the extra wires and have dedicated ground wires run to all lighting 359697



- A35W42B
by:

What was needed to rewire boat trailer. 640879



- A35W42B
by:

Great product. Nice to have two running light wires (brown pin 2)so I could feed running lights and license light without splicing wires... 158701


Comments
Perfectly
Tom F - 10/31/2015

15741

- A35W42B
by:

Website was very helpful as to finding the correct part numbers. My order processed and was shipped in great time! This is my first time dealing with this company, but not my last. I’m recommending to all of my family and friends! 609437



- A35W42B
by:

I recently bought a 2004 Trailstar boat trailer for a boat with a seized engine that a friend is giving me. The trailer was a great deal, but they told me the lights worked and they didn't. The connections were all corroded, none of the side lights were hooked up, and there wasn't enough slack in the existing harness to connect anything to it. Your harness was plenty long and only $15! I just wish that the ground wire was as long as the other wires. The ground wire only reached to the front part of the trailer and there's a hinge with rubber bushings halfway along the tongue. I had to ground the front part of the tongue to the part after the hinge. And then I used the ground wire in the old harness to ground the taillights. 619248



- A35W42B
by:

Harness was exactly what I needed and wanted. Most try to use a 4 wire system (which will do) and then split the running lite wire. 8 times out of 10 they can't get it right and end up taking it somewhere for fitting. etrailer.com had the exact item. Life is good again. quick shipping too. 615822



- A35W42B
by:

The plug looks and feels solid! This is the only place that had a long enough wiring harness to do what I needed. Shipping was also very fast! 471215


Comments
After one year, It is still working great! It makes all the difference having long enough wires to where there is no splicing on a saltwater boat trailer.
Eric - 01/29/2019

49013

- A35W42B
by:

Excellent product and shipping! Let me say all I could find everywhere was 25 ft. The extra 10 feet I get with this item NOW allows me to fix the short in my utility trailer. Thank you so much. 146168



- A35W42B
by:

I want to thank you for all your help with my trailer you were more helpful than you realize. So this is my trailer for a 22' Flats Cat shallow draft Catamaran. I totally dismantled my trailer and buffed by hand with a wire buffer and sand blasted in some spots and applied multiple coats of some very expensive galvanize paint (Z.R.C.). I installed all new C. E. Smith Carpet (about 80'), seven new LED waterproof lights, new springs, new equalizers, new tongue jack, new wench, new safety chain, new chain brackets, all new SS hardware and a 35' long wiring harness. I was able to send only one review with a picture of the safety chain and brackets. I'm having a little trouble with the rest..oh some of these items were bought locally or from your competitors, until I found ETRAILER. Your prices were cheaper for the exact same things. Your helpful how to videos were helpful. And Rose, your personal helpful knowledge made my buying experience very pleasant, I actually enjoyed talking to you! Thanks to ETRAILER and specifically to Rose G. 497941



- A35W42B
by:

I am very satisfied with my experience with etrailer. The parts I received appear to be very good quality. I have not installed them yet though as I am waiting on Hurricane Michael to pass through. However the lights do seem to be very solidly built. I needed this style and etrailer was the one that had it. 572964



- A35W42B
by:

Perfect! Just what I needed!! I could only find a harness plug with one brown wire (4 wires total) at my local stores. I "googled" the problem I had (my harness plug had 2 brown wires). A rep from etrailer had answered someone's same question on a message board. It was a detailed explanation as to why one would need this part. Then the rep put a link to the etrailer site. And there is was, the harness plug with 2 brown wires (5 wires total) and at an agreeable price to boot!!!!! And now I know about the etrailer website!!!! 210017



- A35W42B
by:

Outstanding copper wire harness. Excellent customer service, reasonable pricing, and fast shipping with etrailer.com! Will buy from them again. 825844



- A35W42B
by:

The product arrived in a timely manner and meet my requirements for the job of rewiring a small enclosed trailer that was given to me. 821062



- A35W42B
by:

The replacement trailer wiring is working great after one year. It has not disintegrated and works excellent. It is much better than the cheap stuff I got from eBay 2 years ago that crumbled and I replaced with your superior product. Thanks for the excellent product. 820669



- A35W42B
by:

These guys have exactly what i need for all my utility trailers and with the really fast shipping i dont bother to try to find them in a local store..quality stuff no junk. 819792



- A35W42B
by:

Arrived on time, just as described, solved my issue - what else could I expect? 819302



- A35W42B
by:

I needed to rewire a trailer and wanted a wishbone harness so I didn't have to splice any wires for the brake lights. This harness was just what I was looking for. etrailer.com had a good price and they shipped it out right away. 817984



- A35W42B
by:

1 year later, lights are still doing gr eat. 811725



- A35W42B
by:

Exactly as described, Thank you 807708



- A35W42B
by:

Have not installed product yet, but product was as specified. 806542



- A35W42B
by:

Thanks for having the correct wire length for boat trailers And quality staff and service. 805148



- A35W42B
by:

This product worked great to re-wire my car hauler trailer. The factory wiring was shot and was wire nutted together from the factory with no junction box. This made the install very clean and will make future troubleshooting much easier also. 803832



- A35W42B
by:

1 year later things are still looking g reat! 804618


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Ask the Experts about this Optronics Wiring

  • What is the Wire Gauge on 10 Inch Electric Trailer Brake Magnets
    The magnet wires on Electric Trailer Brake Assembly # A35W42B are 18 gauge. The wiring going to the brakes from a trailer connector is usually larger such as 10 gauge # 10-2-1.
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  • How to Extend Short Ground Wire on 4-Pole Wishbone Harness
    Wishbone 4-pole harnesses like # A35W42B, # A20WB, # W002230 and # A10-4225VP usually do have a short ground wire because most trailer frames are steel and they conduct well enough that a ground wire attached near the tongue will provide sufficient ground even for lights mounted all the way at the back of the trailer. On the other hand if you have an aluminum frame trailer that does NOT conduct electricity nearly as well as a steel frame then you might need to extend that 2- or 3-foot...
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  • Troubleshooting Trailer Brakes Where Only One Assembly Locks Up
    The brake assemblies all will receive the same amount of power from your brake controller so the issue is the brake assembly that is locking up. Most likely it's adjusted tighter than the others which is causing it to lock up sooner. That would be the first thing I'd check. The trailer wheels should be able to turn by hand if they are off the ground but you should be able to hear the brakes drag on the drum slightly. Check to see if the one that locks up is harder to turn and that would...
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  • What is Wire Gauge of Optronics 4-Way part # A35W42B
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  • How to Wire Second Axle of Trailer for Brakes
    Yes, you can jump the front axles brake output circuit to power the rear axle. Check out the picture I attached to see how most people do this.
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  • How Does the 35 Foot Wishbone 4-Way Trailer Wiring Harness # A35W42B Function
    The way that the 35 foot Wishbone 4-Way Trailer Wiring Harness, # A35W42B, works is instead of having 1 taillight wire (brown) that you would need to splice into in order to run to both taillights, this harness has two wires (one attached to each stop/turn signal wire). The wires are attached to each other (except at the 4-Way connector) so you cannot mix them up. This would be good for your application since you will not have to splice wires that could end up being exposed to the water....
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  • Troubleshooting a 4-Way Wishbone Trailer Connector Without Running Lights
    Traditionally, the brown wire is the running lights. On your trailer you have a 4-way wishbone connector, similar to our part # A35W42B. With a wishbone the running light circuit is ran on two wires one going to each side of the trailer. This usually makes wiring the trailer easier. Do you have running lights at the vehicle's connector? Use a circuit tester, like part # 40376, to test each function on the back of your tow vehicle. This will isolate whether the problem is with the...
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  • How To Wire a 5th Wheel for Triple Towing a Trailer with Brakes
    It is possible to triple tow (1 tow vehicle + 2 trailers) when both trailer's have brakes but this would mean that the brake output wire that runs from the brake controller in the tow vehicle to both trailers would need to be at least a 6 gauge at the minimum so you don't have issues with voltage drop. Also, the number of braked axles cannot exceed what your brake controller is capable of handing which most are usually four. In order to obtain the needed length of 6 gauge or greater wire...
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    Typically trailer wiring is color coded. The brake circuit is usually a blue wire which travels to each brake magnet, where it is attached to one wire from each brake magnet. The other wire from each brake magnet will ground to the trailer frame. I have attached a drawing that shows how the wiring is typically run for brakes on a trailer. I have also attached a link to trailer wiring diagrams that may help.
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  • How To Wire A 7-Way Trailer Connector With A Wishbone Trailer Wiring Harness
    The best way to wire a 7-way plug on your trailer that has a 4-way wishbone harness is to use a junction box like part # 38656 from Spectro. The wishbone harness has two separate running light brown that connect both sides of the trailer running lights without the need to run a jumper wire between the two sides of the trailer. The # 38656 junction box will give you a nice way to wire together the trailer's leads and the 7-way plug like Hopkins part # H20044. You would use the junction...
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  • Tracking Down Possible Poor Ground Connection on Travel Trailer
    What you're describing is the classic symptom of a poor ground connection somewhere in your trailer lighting system. When all the functions are being used, you're drawing maximum amperage through the system, which is when a ground problem will manifest itself. Trace the white ground wire back from the trailer connector. The wire will usually ground to the trailer frame somewhere on the trailer tongue. Make sure this connection is secure and not corroded. Each trailer lamp will also have...
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    The longest 4-way harness we offer that has all 16 gauge wire is the Wesbar Harness part # W787274 which is 14 feet long. For one that is 30 feet long that has a 16 gauge ground wire and 18 gauge signal wires you would want the part # W002230.
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