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Hopkins Wiring Harness with 4-Pole Flat Trailer Connector - Trailer End - 4' Long
Hopkins

Hopkins Wiring Harness with 4-Pole Flat Trailer Connector - Trailer End - 4' Long

Part Number: HM38138
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$4.76
Retail:$5.84
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Trailer Wiring
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Wire your trailer with this universal, splice-in wiring harness so that you can connect the trailer's wiring to your vehicle's during towing. Corrosion-resistant terminals are long-lasting. Meets SAE standards. Great Prices for the best trailer wiring from Hopkins. Hopkins Wiring Harness with 4-Pole Flat Trailer Connector - Trailer End - 4' Long part number HM38138 can be ordered online at etrailer.com or call 1-800-940-8924 for expert service.
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  • Reviews (60)
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  • Videos (1)
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Hopkins Trailer Wiring - HM38138

  • Trailer Connectors
  • Trailer End Connector
  • 4 Flat
  • Plug and Lead
  • 0 - 5 Feet Long
  • Hopkins

Wire your trailer with this universal, splice-in wiring harness so that you can connect the trailer's wiring to your vehicle's during towing. Corrosion-resistant terminals are long-lasting. Meets SAE standards.


Features:

  • 4-Way flat trailer-end connector plugs into the 4-way flat on your vehicle
  • Simple installation
    • Hardwire to existing trailer wiring
  • Corrosion-resistant terminals are long-lasting
  • SAE compliant


Specs:

  • Harness length: 4'
  • Wiring configuration:
    • White: ground wire
    • Yellow: left turn/brake light
    • Green: right turn/brake light
    • Brown: tail lights
  • 90-Day limited warranty


38138 Hopkins 4-Way Flat Connector - Trailer End - 48"

Installation Details HM38138 Installation instructions


California residents: click here


Video of Hopkins Wiring Harness with 4-Pole Flat Trailer Connector - Trailer End - 4' Long

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




Video Transcript for Hopkins Wiring Harness with 4-Pole Flat Trailer Connector Spec Review

Today we're going to be taking a look at the Hopkins wiring harness with a 4-pole flat trailer end connector. The 4-way flat trailer end connector is going to plug into the connector from your vehicle to power your trailer's signal lights. Pretty simple installation. It's designed to just hard wire to the existing trailer wiring. On the connector portion right here, it's going to feature corrosion-resistant terminals, so these are very long-lasting, and it's got a nice easy-grip design, which allows for simple plugin and disconnect. The overall length of our harness is going to measure about 4 feet long. When it comes to the wiring configuration, you're white wire's going to be your ground.

Your yellow wire's going to be for your left turn brake. Green is for right turning brake, and brown is for your taillights. That's going to do it for today's look at the Hopkins wiring harness with a 4-pole flat trailer end connector.

Customer Satisfaction Score:


Customer Reviews

Hopkins Wiring Harness with 4-Pole Flat Trailer Connector - Trailer End - 4' Long - HM38138

Average Customer Rating:  4.9 out of 5 stars   (60 Customer Reviews)

Wire your trailer with this universal, splice-in wiring harness so that you can connect the trailer's wiring to your vehicle's during towing. Corrosion-resistant terminals are long-lasting. Meets SAE standards.

by:

Perfect! extra long so I got rid of all my bull crab wiring



by:

This replaced a old plug.



by:

Well made, especially the mounding around the plug. Pin alignment was very good.



by:

The wiring harness is cheap and easy. < br>


Hopkins S. profile picture

Hopkins S.

5/11/2017

Thanks for the review on the Hopkins Wiring Harness, Nick! Hopkins appreciates your business.



by:

The Hopkins Wiring Harness was exactly what I needed to repair the trailer. Very affordable.



by:

Great product for the money I had replace my trailer wire at the trailer connector end , the wires are even labeled .



by:

Nice quality wire and connector that is still working well after a good summer worth of use



by:

GREAT PRICE, SERVICE & FAST SHIPPING



by:

Parts as described, spare tire and rim for my utility trailer, fast shipping, able to order exactly what I needed, recommend!



by:

Worked perfectly



by:

Excellent. Fit the factory installed tow vehicle connection perfectly. (F250) Easy to install and worked as it should.



by:

I've only had the products for a couple of days so I can't vouch on quality. Looks good. Doing business with etrailer was a good experience.



by:

Product performs as expected, distributor stand behind products in accordance to need.

Hopkins S. profile picture

Hopkins S.

5/23/2017

Thanks Sam for reviewing the Wiring Harness!! Hopkins appreciates your business.



by:

Worked as a great replacement for the old/failing plug on my parent's trailer!



by:

The product was as advertised...good quality at a very reasonable cost.
Delivered expediously.
Thanks



by:

Love all your products. Love how fast you get them out and on the way.



by:

Good quality. Fast shipping.

David F. profile picture

David F.

6/7/2020

still working great



by:

Fixing the trailer issue.



by:

easy to find anything i need , great price and service. no need to go anywhere else,fast delivery.

Hopkins S. profile picture

Hopkins S.

5/31/2017

Thanks Pa John for the great review and rating!! Hopkins appreciates your business.



by:



by:

Exactly what I was hoping for, excellent quality and easy to install. I would definitely purchase again.



by:

real good quality,

Hopkins S. profile picture

Hopkins S.

6/21/2017

Thanks for the review on the Hopkins Trailer Connector, Jim!! Hopkins appreciates your business.



by:

Worked exactly as expected, decent quality wire.



by:

Very pleased. Exactly what I wanted a a very fair price. Shipping was fast. I would definitely order from them again and probably will.



by:

quality product


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Show More Reviews

See what our Experts say about this Hopkins Trailer Wiring

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    The Blue Ox Tail Light Wiring Kit with Block Diode # BX8811 that you referenced does not come with a 4-Way connector as you stated. To add a 4-Way connector you can simply use the Hopkins Wiring Harness with 4-Pole Flat Trailer Connector # HM38138 and connect it to your current wiring using Butt Connectors # DW05744-5. For a look that is a little more clean and will provide you with a 7-Way to connect to your RV you can use the Hopkins Nite-Glow Tow Bar Extension Cord w/ Socket - Coiled...
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  • Troubleshooting Trailer Wiring After Installing Lights And Wiring
    There could be a couple of reasons why the lights are not working now. You said you replaced some lights and wiring. I recommend checking all of the connections to make sure everything is secure and wired properly. You can use a circuit tester like part # PTW2993 to make sure all of the lights and wires are receiving current as designed. If everything checks out the problem is probably the ground connections. Check the inside of the trailer connector for corrosion. If you find any green...
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  • Do 4-Way Connectors Have a Power Wire
    Trailer and vehicle 4-way connectors like you'll find with the 4-Way Flat Trailer Wiring Kit - Vehicle and Trailer Ends # HM48205 do not actually have a hot - or power - wire. As you can see by the cut out I added of the linked help article on trailer wiring (which I highly recommend checking out), a 4-way will activate running lights, brake lights and turn signals. I have added a link to our entire selection of trailer end 4-way connectors for you to take a look at.
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  • Parts Needed to Re-Wire European Trailer to RV-Style Trailer Wiring
    Thank you for the photo of your trailer's European wiring. You will be best served by replacing the Euro style connectors on your trailer to the RV-type. We do not offer Euro style wiring harness kits for vehicles. The part you referenced, adapter # 118710, adapts a European vehicle to a 4-pole type connector but does not adapt the trailer to match U.S. wiring. Euro wiring has every function on a separate wire; while here in the U.S. trailer wiring combines the stop and turn signals. The...
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  • 4-Way Trailer Wiring Recommendation that Uses all 16 Gauge Wires
    For a 4-way that has all 16 gauge wire you would want the Wesbar 4-Pole Flat Connector # W787264. The part # HM38138 uses 18 gauge for all wires but the white that uses 16 gauge.
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    The best way to connect the 4-Way to your trailer wiring is going to be to test each of those wires by applying 12V power to them. By doing this you will be able to see what each wire activates on the trailer to verify their function. Going by wire color alone, as you are seeing, isn't always a good idea because trailer manufacturers or previous owners have a tendency to use non-standard wire colors. Once you determine their functions the trailer wire for left turn/brake light will go...
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  • Can Trailer with Brown Yellow and Brown Green Wires Run to Standard 4-Way
    Yes you would be able to use your current trailer wiring configuration with a standard 4-way that only has 4 wires like the # HM38138 that you referenced. Basically the yellow brown and the green brown wire would wire directly to the single brown wire of the 4-way and the other colors would match and you'd be set. What you have now is a wish bone setup that just has a separate wire for the running light circuit for each side of the trailer. We have 4-ways that are setup for this with the...
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  • Converting Euro 7-way To Standard 4-Way Flat Trailer Connection
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Info for this part was:

Employee Lindsey S
Edited by:
Lindsey S
Employee Jameson C
Expert Research:
Jameson C
Employee Adam R
Expert Research:
Adam R
Employee Jeffrey L
Expert Research:
Jeffrey L
Employee Cole B
Installed by:
Cole B
Employee Alexander C
Written by:
Alexander C

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