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7-Way Molded Trailer Wire Connector - 3' Long

7-Way Molded Trailer Wire Connector - 3' Long

Item # H20042
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Lowest Prices for the best wiring from Hopkins. 7-Way Molded Trailer Wire Connector - 3' Long part number H20042 can be ordered online at etrailer.com or call 800-298-8924 for expert service.
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Hopkins Wiring - H20042

  • Trailer Connectors
  • Trailer End Connector
  • 7 Blade
  • Plug and Lead
  • Hopkins
  • 0 - 5 Feet Long


Trailer Connector RV Style 7-Way Blade with 3' lead

  • Pre-wired 7-Way Trailer Connector
  • Measures 3 feet long including connector
  • Wire gauges:
    • 14-Gauge - red, brown, green, and yellow
    • 12-Gauge - blue
    • 10-Gauge - white and black


Wiring Code
Molded Connector Function Usual Trailer Wire
White Wire Ground White Wire
Red Wire Left Turn and Brake Yellow Wire
Brown Wire Right Turn and Brake Green Wire
Green Wire Tail Lights Brown Wire
Blue Wire Brake Power Blue Wire
Black Wire 12 volt (hot lead) Black Wire
Yellow Wire Aux. -



20042 7-Way Molded Trailer Wire Connector, 3' Long

Installation Details H20042 Installation instructions


California residents: click here


Video of 7-Way Molded Trailer Wire Connector - 3' Long

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




Video Transcript for Trailer Wiring Harness Installation

Today in this old trailer, were going to install part number is H20042. This is a molded 7-pole connector with a three foot lead. Now to install this, were also going to use a junction box. Now our junction box is going to be part number 38656. Now to start off, were going to find a location for our junction box. So first well go ahead and put it in place where we want it and then mark our holes.

Well then go ahead and remove the box and then drill out our holes. Next, using some quarter-inch hardware, well go ahead and test fit it into place. If its a really tight fit, it might be helpful to enlarge the holes just a little bit. Now were going to leave one end connected and let the one swing out. Well remove the lid and well start working on our 7-pole connector.

First off, we need to install a bushing around the wire. Now this comes with a junction box. Well go ahead and slide it into place and do a test fit. We may have to trim back some of the cable sheath to make everything fit inside box. Now well go ahead and add our ring terminals to the end of our wires.

Were going to put ring terminals on our blue wire, green wire, brown wire, the red wire and a white wire. Once we have these connected, well go ahead and hook them up to the pins in our junction box. Now were going to hook these up by function not by color code. Our blue wire will go to our blue harness case labeled auxiliary on the box. Our green wire will go to function running lights labeled brown.

Or brown wire will go to the function labeled right turn, but youll have a junction box labeled green. Our red wire will go to left turn also labeled yellow in the junction box. And our white wire will go to the pin labeled white and also labeled as ground. We got our 7-pole connector wires in place and now well go ahead and add our trailer wires into place. Well need to go ahead and add some ring terminals to those to and also after we have the ring terminals installed, we can actually go slip through one of the bushings that are pre-existing in the box just by putting a slit in them and pushing them through. Were adding the brown, the green and the yellow and black wire will be from the trailer electric brakes. And well add a fifth wire, which will be white to ground. Well hook up our black wire to function AUX also labeled as blue. Our brown wire will go to the running light function also labeled as brown. Our green wire will go to the pin labeled right turn also labeled green. And our yellow wire will go to our left turn signal also labeled yellow. And then finally, well add a white wire for ground and thatll go white to white. Once we have all our wires in place well go ahead and attach the nuts to hold them down and tighten them down for good. And then all we need to do is go ahead and take our white wire and attach the other end of it to our preexisting grounds on the frame. With all our wires secured in a junction box, last thing we need to do is go ahead and apply some clamps to the inside edges where the wires come into the box. Thatll keep them secure and from moving around anymore than they have to. Then well install the lid and then inaudible 00:04:59 the box permanently on the inside edge of the frame. Okay and with that, were finished. There you have it for part number H20042, The 7-Way Molded Trailer Wire Connector from Hopkins. .


Customer Reviews

7-Way Molded Trailer Wire Connector - 3' Long - H20042

Average Customer Rating:  4.6 out of 5 stars   (145 Customer Reviews)


- H20042
by:

I've had this in use for over a year and they don't build them like they use to. I use this on a gooseneck trailer and the piece of plastic behind the spade connector for the clearance lights and brakes has melted, allowing the spade connector to lose contact with the plug on the pickup. So the lights would cut off in the middle of the night and would have to wiggle the connection till I could fix it. I have an older Hopkins plug and never had this problem. To fix the problem I ended up putting pieces of thin copper wire behind the spade and have done it twice since the plastic melted a 2nd time and once again the trailer clearance lights would quit working. Attached are before and after pictures. 463245



- H20042
by:

Etrailer always has the hard to find items along with a good selection. I’ve been shopping with them over the years and they are a go to shop. 786361



- H20042
by:

Excellent product. Also etrailer was very helpful when I needed help installing . Great place to do business. 768178



- H20042
by:

Wire color scheme was totally wrong for my Tundra, it’s a poor fit in the socket and it’s a touch too short. When I first hooked it up I had my running lights as blinkers and my reverse lights controlling my brakes. AVOID 666842


Comments
There is more than one accepted wiring color code, which is why we identify the wire color and each wires function in the product description above.
-- Mike L - 07/08/2019

57570

- H20042
by:

Wired to my Lance Camper harness to avoid having the Lance custom socket in the bed wall when I upgraded my truck. I had to run an 8 ga 12v source from the truck battery to the rear of the bed to supply lots of 12v power for the camper fridge. I didn't use the weak 12v supply from the stock truck trailer connector. 665571



- H20042
by:

Product worked fine for what I needed. Plug on my tow vehicle was further away from the ball than it was on my old one. Trailer pig-tail was not quite long enough to provide slack for turns. I put the other end on this pig-tail and extended the trailer pig-tail. Worked great. 657636



- H20042
by:

Looks well made. I have no idea if it is made in USA though. I wish etrailer would give country of origin (when not USA). MAGA! 640697


Comments
Good quality. Easy to work with.
Dennis - 05/11/2020

76205

- H20042
by:

Was just what I needed works well. I stock these now for my customers 577200



- H20042
by:

Great product, excellent company to do business with. 573410



- H20042
by:

product was as described in catalog. completely satisfied. 573254



- H20042
by:

Great products with great customer service. Mailed same day!! 560322



- H20042
by:

Thank you. Used for conversion from hydraulic brakes to electric 548214



- H20042
by:

I bought an adjustable Curt receiver and my trailer wiring ended up being a few inches to short, it was tight to begin with. I was going to buy an extension but they were around 7' long, which was to long for my needs. I chose this and wired it up the other day and it works great so far. Make sure you have the RV blade type like this connector not the pin type or it won't work obviously. As mentioned in other reviews, the wiring may be color coded different on your trailer, so be mindful of that or you'll be re-doing the connections. It looks like a sturdy and well built sealed connector, so it should last for years and it was reasonably priced. 523714


Comments
We always recommend to test by function before connecting any wiring using a circuit tester like part # 3808. I have also included a link to one of our help articles that shows the different wiring configuration options.
-- Rachael H - 06/20/2018

40013

- H20042
by:

thanks for your help 514051



- H20042
by:

Excellent product. Much higher quality than I expected at this price. Online wiring guide is great. Would be good if paper copy accompanied product to avoid mistakes I made first time I connected harness. Excellent quality. 499167



- H20042
by:

Not a problem. Working fine so far. 493000



- H20042
by:

Good service 490796



- H20042
by:

Great product for a great price. Molded plug to repel moisture 482903


Comments
Everything still works great. Thanks.
Jeremiah - 03/09/2019

50333

- H20042
by:

Good replacement for the one that i had that got damaged. 469025



- H20042
by:

Great connector at a great price. 463664


Comments
Product is working fine after a year. Happy New Year.
Calvin R - 12/29/2018

48064

- H20042
by:

The quality of the material and construction appears to be fine. The overall length of the item was short of what was advertised. It'll still work for my project, but I guess it is buyer beware. Wonder if I'd have received the product if I sent less money????? 461252



- H20042
by:

Great part, very fast shipping. Thank y ou. 444616



- H20042
by:

Excellent service and fast delivery. You will be first on my list for anything else I need. 434764



- H20042
by:

Works 428313



- H20042
by:

Everything arrived faster than I thought it would and everything looks great!!! I will be buying more when I need trailer parts in future. Things should go alright installing unless I screw it up. 427534


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Show More Reviews

Ask the Experts about this Hopkins Wiring

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    Easiest solution we can offer for replacing the 7-way and lead of your Prodigy RF part # 90250 is to hardwire in the part # H20042 in place of the one you lost. Or you could even cut the loom on both side of what you have, strip back the wiring, and then butt end connect all of the connections. For a set of ten butt connectors you'd then want the part # DW05745-10.
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  • Recommended 7- and 4-way Bumper Plug Extension for Use with Cabover Camper
    I have just the thing for you to extend your bumper plug to the end of your camper. If you want to get the 7-way and 4-way you will want the # H20042 and the # HM48470. This combination will need to be wired up but will include the mounting bracket for the 7-way and 4-way. If you prefer to have a prewired 7-way the one you will want it the # TLW6021. All of our prewired ones will only include the 7-way. A mounting bracket for this extension plug is # TM76474. I have linked all...
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  • Replacement 7-Way and Wiring Diagram for Camper
    Sorry to hear about the vandalism of your camper. I attached a couple diagrams for 7-way trailer wiring harnesses. For a replacement 7-way we have the part # H20042 which comes with 3 feet of wire.
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  • Recommended Solution for Towing European Trailer with US Vehicle
    The best thing I can recommend you do is you would want a trailer side 7-way like part # H20042 to wire up to an EU socket found local to create an adapter to use your US spec vehicle with EU trailer wiring. I attached a chart that labels the functions of the wires on this connector for you to reference. To gain all the function that a US 7-way carries you will also need to adapt your US 4-way into a 7-way blade to be compatible with the # H20042. For this I recommend the # ETBC7,...
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  • 7-Way Wiring Kit to Upgrade Trailer Wiring on 1999 Viking Pop-Up Camper Trailer
    Since your Viking pop-up camper trailer's wiring is of a different format than the standard 7-way on your 2017 Chevrolet Silverado 1500, which has a 4-pole and a 7-way combination connector, the best long-term solution is to wire in a new 7-way male plug on the trailer using a kit like # e99011. This kit includes the 7-way plug and cable, a wiring junction box and all connectors required to update your trailer to the modern 7-way RV format. The Jayco 6-pole square connector type, which...
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    For all the functions you are looking for you would want to install a 7-way and then use a junction box to organize the wiring. Starting with a trailer side 7-Way connector you can use # H20042 which is 3 feet long. It doesn't have to be long though because it is going to the junction box. Speaking of junction boxes you can use # 38656. I have included a picture showing how it can be wired up and a video showing installation to the right. For the rest of the wiring you can use ...
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  • Functions of the White, Blue and Black Wires of the Replacement 7-Way H20042
    The white is ground, the blue is for the brake output circuit for the trailer's brakes and the black is for the auxiliary 12 volt circuit for the trailer. If you have no use for these circuits then they would not have to be connected to anything, you would just need to tie them up and out of the way. I attached a chart that shows the functions of each of the circuit of the connector. I attached an install video for you to check out as well.
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  • Compatibility of Hopkins 7-way Trailer-Side Connector # H20042 with 2004 GMC Sierra 2500
    The Hopkins 7-Way Molded Trailer Connector you mentioned, part # H20042 is not a vehicle-specific item. It will work well with any vehicle that is equipped with a 7-way trailer connector as long as it is wired correctly. I have linked you to our wiring FAQ article that will run through how a 7-way is wired. Keep in mind that the # H20042 uses a non-typical wire color code, so be sure to wire it by function, not by wire color. The white wire on the connector would ground to the trailer...
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  • Wiring In the Hopkins 7-Way Molded Trailer Wire Connector, # H20042
    I will be glad to help you out with wiring up your trailer. To start, I will mention the electric brake wiring. There are 2 wires on the brake assemblies coming from the magnets. One will be ground and should be connected to a bare metal surface on the trailer frame, near the magnet. If the ground is too far away, it may not work properly. The other wire will connect to the blue wire on harness # H20042. This will provide the power to the brakes. The White wire is the ground and it does...
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  • 7-Way Replacement Recommendation for Bunkhouse Camper with 6-Way Flat
    We don't have a 6-way flat connector so we don't have a way to create an adapter using one. Only solution we have would be to remove the 6-way flat and install a 7-way flat in it's place like with part # H20042.
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  • Does Hopkins 7-Way Trailer Connector Have a Wire for Reverse Lights
    Yes, the yellow wire is labeled as auxiliary in the chart on the product page. This wire goes to the center pin which on your Dodge Ram would be the reverse lights. I assume you need this to activate the back-up solenoid for a reverse lock-out so the brakes do not engage when backing up.
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  • How Would Trailer with 4-Way Wire to the 7-Way part # H20042
    It sounds like your current 4-way has two wires ran to the running light circuit (one for each side of the trailer) and the rest of the wiring is standard. Especially considering the order of the colors that you listed. Green is right turn/stop, yellow is left turn/stop, brown is running light, and white is ground. To wire that to the part # H20042 that you referenced would require you to use the information I just listed and compare that to the diagram picture that I attached. You would...
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  • Installation of Hopkins 7-Way Molded Trailer Wire Connector Based on Wire Function vs. Color
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Info for this part was:

Expert Research:
Jackie C
Expert Research:
Mike L
Expert Research:
Robert G
Expert Research:
Patrick B
Expert Research:
Michael H
Expert Research:
Jameson C
Expert Research:
Adam R
Video Edited:
Zack K
Installed by:
Cole B
Updated by:
Sarah W
Updated by:
Alexander C

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