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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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Trailer Wiring A35W42B - 31 Feet and Longer - Optronics
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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. 35 Ft 4-Way Trailer Wiring Harness - Wishbone Style - 42" Ground part number A35W42B can be ordered online at etrailer.com or call 1-800-496-5010 for expert service.
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Optronics Trailer Wiring - A35W42B

  • Trailer Connectors
  • Trailer End Connector
  • 4 Flat
  • Plug and Lead
  • 31 Feet and Longer
  • 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: 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   (619 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:

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.




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!


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


by:

Nice harness plug is much nicer than your typical cheap wiring harness more along the lines of a wesbar.




by:

I ordered the 4 way trailer end plug/wiring assy (35 Ft 4-Way Trailer Wiring Harness - Wishbone Style - 42" Ground
Item # A35W42B), and it was at my house in about 3 days! And at a great price to boot!!

I checked around all of the local auto parts stores, and none even had this product on hand! I'm bypassing the local stores now when J can, and ordering strictly from etrailer. Their prices are great, product selection is beyond any others I've seen. And their professional and informed people never fail to follow up with a complimentary email to make sure everything is to my satisfaction.

If you're looking for towing-related items, look no farther than etrailer!!




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!!!!




by:

Order was shipped the very next day after placing it. E trailer sells reputable, quality products. I have always been pleased with the trailer related parts I have ordered.




by:

I ended up doing some metal work installed new leaf pins/bushing on that trailer, sandblasted, new paint/deck. so just installed about a month ago and works great . Quality wire should last. Thanks as always.




by:

This worked great, had to rewire my trailer after having it painted and reconfigured and this item was long enough and allowed me to tie in my additional lights.




by:

I have purchased twice for 2 separate boat trailers from etrailer. If you utilize a flat 4 plug as I do, they are a must. The harness coils nicely with ample extension. The harness is well built as is the majority I purchase from etrailer.




by:

Like the "y" design. I have rewired alot of trailers and really made it simpler




by:

Awesome service


Comments
All great and awesome service
Danny - 07/23/2022


by:

I purchased this to update my very old and non-functioning pontoon trailer wiring. I needed the extra length and was glad etrailer provided it as an option. Since the new wiring harness was already set up to run each side separately, it made easy work of rewiring the trailer. I really like etrailer products. I think they are of good quality for a good price. Sorry, no photos of the job.


Comments
Working like a charm. Still happy with the product and the outcome.
Lauri - 05/18/2021


by:

I paid for UPS shipping and it came two days late via USPS ; got ripped off from shipping costs




by: 03/08/2021

Good quality, inexpensive


Comments
Excellent
Scrapper - 03/08/2022


by:

Absolutely Fabulous! Exactly what I was looking for but couldn't find at any retail store in my area! The wishbone design splits the brown wire at the plug. Makes wiring both sides of the trailer with no splices or having to find additional brown wire sold by the foot!




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!




by:

The wiring harness worked great.the extra length made it easier to install without splicing the wires




by:

Good price reasonable quality
This wiring
harness has worked well since I installed it about an year ago




by:

Package arrived early, exactly what I ordered and in perfect condition.


Comments
Product continues to work as expected.
Dean - 03/01/2022


by:

Wires installed easy and worked for a couple of months. After getting the boat ready this spring I noticed that despite using watertight shrink wrapped and liquid electrical tape sealed connections the wires had completely corroded and now need to rewire the trailer all over again.




by:

Just received it in the mail yesterday. Appears to be what I expected. If the wire proves to be good then all is as it should be.




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.




by:

Excellent product and would buy again!!




by:

Exact What I needed. It worked great.


Comments
I sold the trailer the other day. Lights were still working fine.
Scott - 02/22/2022


by:

I have not received my order


Comments
I will have our Customer Service team reach out to you.
-- Etrailer Expert Jenny N - 04/08/2022

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Show More Reviews

See what our Experts say about this Optronics Trailer Wiring



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    Your main problem is an insufficient ground for the trailer wiring. Try improving the connection of the main ground wire of the trailer wiring harness. Make sure it is attached to a clean metal surface. Or you can run all of the trailer wires back to the main ground. This is actually the ideal solution. But you can also check the current grounds for the lights to make sure they are making a solid connection to a clean metal surface. What you described is the classic insufficient ground...
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    I'm not sure what the sensor you describe is for. Typically trailer wiring is color coded so that right turn and brake light signal is carried by a green wire, and the brown wire carries the running light circuit. The brake output circuit is usually carried by a blue wire which travels to each brake magnet, where it attaches to one lead from each magnet. The other lead from each magnet will ground to the trailer frame. I'll give you a link to a typical trailer wiring diagram. I also...
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    Assuming that your trailer uses a 4-Pole connector, we have exactly what you need. The Wishbone 4-Way Trailer Wiring Harness, part # A35W42B would work perfectly for you. The wire for the running light circuit is actually split into two wires, one to run down each side of the trailer. As each running light wire runs down the side of the trailer, tap your side marker lights into this circuit and continue running it to the rear lights.
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    The 4-way flat trailer harness I recommend is the Optronics 35 ft. Wishbone 4-Way Trailer Wiring Harness with 42" Ground Wire # A35W42B. This harness is a wishbone and that means it will have a tail light wire on each side of the trailer so you won't need to run a jumper across the frame. This harness makes it quick and easy to wire your trailer. This harness is compatible with any 4-way flat vehicle side trailer connector like the T-One you referenced. I've attached videos for your...
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