Select Your Vehicle
view cartView Cart

Free Shipping on Orders Over $99

Only 21 Hours 33 Minutes Remaining

Custom Fit Vehicle Wiring > Trailer Hitch Wiring > No Converter > 4 Flat > Universal Fit > Hopkins

Hopkins Endurance 4-Way Flat Trailer Connector Socket - Vehicle End - Ergonomic Design

Hopkins Custom Fit Vehicle Wiring

ratingratingratingratingrating (6 reviews)

Code:   HM48030


Shipping Special

Shipping Weight: 0.5 pounds


Hopkins Custom Fit Vehicle Wiring - HM48030

This heavy-duty 4-way flat trailer connector socket mounts on the vehicle. A weatherproof, insulated lid covers the terminals and the large grip makes connecting the plugs quick and easy.


  • Easy pull, over-sized grip - makes connecting/disconnecting quick and easy
  • Heavy-duty housing with dust cover protects the terminals
    • Housing also has mounting holes to connect to brackets or bumper
  • Terminal grease packet included
  • 4-way flat socket (vehicle side)
  • Works with all 4-way flat connectors


  • Wires: 48" Long
  • Pigtail leads with ring terminal installed on ground wire
  • Wire Configuration:
    • Yellow - left turn and brake
    • Green - right turn and brake
    • Brown - tail
    • White - ground

48030 Hopkins Enurance 4-Wire Flat Trailer Connector - Vehicle Side

Customer Reviews

Hopkins Endurance 4-Way Flat Trailer Connector Socket - Vehicle End - Ergonomic Design - HM48030

Average Customer Rating:  ratingratingratingratingrating5.0 out of 5 stars   (6 Customer Reviews)

This heavy-duty 4-way flat trailer connector socket mounts on the vehicle. A weatherproof, insulated lid covers the terminals and the large grip makes connecting the plugs quick and easy.

- HM48030

ratingratingratingratingrating by: Danny W.07/25/2013

Product was awesome. My last two connectors have corroded so bad within a year that I constantly was having to take a wire brush and clean off the pins to get good contact. I'm waiting to see what the environmental cap does to eliminate me having to do this. Also bought the vehicle side. Would highly recommend this to anybody with a trailer hook-up. Only thing I would suggest is to make sure anybody purchasing also buys the splices since none come with the product. All in all, a great buy. Thanks! 91415


Using dielectric grease in the trailer connectors can also help reduce corrosion of the contacts.

Patrick B - 07/31/2013


- HM48030

ratingratingratingratingrating by: Ron K07/11/2014

Did lot of searches for an item like this and found it only on etrailer. Ordering was easy, communication was excellent and shipped promptly. Item looks to be well made and I can install it by drilling only one hole. Exactly what I needed for my application. 140829

- HM48030

ratingratingratingratingrating by: Wayne W.02/24/2014

Well made and delivered exactly as ordered. I used it in a custom wiring harness for a tow dolly. I wanted to provide a connection for magnetic based lights to place on the towed vehicle. It was perfect for my application. 117500

- HM48030

ratingratingratingratingrating by: Edd V.11/04/2013

Product was top quality. Exactly how it is described on the web site. fantastic company to deal with. Great prices and great service. 106209

- HM48030

ratingratingratingratingrating by: Barry S04/02/2012

Heavy duty, quality with protective cap. Much better than OEM equipment. 35909

- HM48030

ratingratingratingratingrating by: D.R.06/25/2012

Excellent products and service!!! 45528


Ask the Experts about this Hopkins Custom Fit Vehicle Wiring
Expert Answers about Hopkins Endurance 4-Way Flat Trailer Connector Socket - Vehicle End - Ergonomic Design - HM48030Do you have a question about this Custom Fit Vehicle Wiring?

  • How to Make a 6-Way Square to 4-Way Flat Trailer Wiring Adapter
  • The 6-Way square trailer connector is not used by a lot of trailer manufacturers. A lot of Jayco trailers may have them but mostly you come across the 4-Way flat, like what you have on your trailer, and the 7-Way blade for RV applications. What I recommend is to convert the 6-Pole on the Monaco to a 4-Way. You can do this very easily by removing the 6-Way plug, and then testing the wires for function using a circuit tester like # 3808 if needed before installing them in a new 4-Way,...
    view full answer...

  • How Come this 6 Way Square Adapter # 30104 Will Not Work on My 1983 Coleman Pop Up
  • The reason you are not getting the lights to work is that this Adapter 4 Way Flat to 6 Way Square for Jayco, part # 30104, is because this adapter is wired to only work on Jayco trailers, and is not wired to work on your Coleman Pop up. Although we can not sell you an adapter that would work on your Coleman trailer because of propriety issues with Coleman, there is a way you could get your trailer lights to function properly. You will need to connect the # 30104 to your vehicle and...
    view full answer...

  • 4-way Options for use With a Tow Ready Mounting Bracket
  • The Hopkins 4-way # HM48030 that you referenced is a great 4-way, but like you noticed, it is much larger than most 4-ways so it would not fit through the Mounting Bracket 4-Pole Flat # 18144 that you have. You basically have two choices at this point. You can either buy a different 4-way that will fit through the hole of the # 18144. Or you could cut off your # HM48030 and then run the wires through the front of the # 18144 and then reconnect the wires to the 4-way wiring of your vehicle. Check...
    view full answer...

  • How to Connect the Ground Wire on a 4-Way Flat Wiring Harness
  • The Hopkins Endurance 4-way Flat Trailer End Connector, # HM48110, that you referenced is the harness that goes on a trailer, not a vehicle. The 4-way connector for your vehicle is the Hopkins Endurance 4-Way Flat Vehicle End Connector, # HM48030. You can connect the white ground wire from the wiring harness to a vehicle ground, but you should verify that the white wire on your vehicle is in fact a ground wire. In most cases the white wire from the wiring harness is attached to a clean,...
    view full answer...

  • Running Lights Work But Brake Lights and Turn Signals Do Not Work on Coleman Camper
  • The best way to start troubleshooting your truck and trailer is to disconnect the two and test each one separately. If you have access to a different tow vehicle or trailer you can test using one of these to isolate the problem to either your truck or camper. Inspect both the vehicle and trailer connectors for signs of dirt, discoloration or corrosion. Even very slight greenish or whitish discoloration on the connectors can interfere with signal transmission. You can try cleaning the...
    view full answer...

  • No Tail Lights On Boat Trailer When Parking or Headlights of 1995 Ford Truck Are On
  • It sounds like you have a common ground problem. When the headlights are on, the highest amperage draw is placed on the wiring system and if you have a bad or loose ground, you will have problems with lights. You will want to inspect to make sure all the light assemblies have a good ground connection to a clean, rust and paint-free metal surface. You will also want to make sure the trailer and vehicle side connector have a good ground connection. I would recommend unbolting the ground...
    view full answer...

  • Preventing Damage to 4-Way Connectors on Trailers Used by Many People
  • There are a few solutions I can think of. First I will list some parts that you may find useful then explain some of the ideas I had. We offer a weather proof junction box, part # 38656, that would allow people to make hardwire connections without cutting your 4-pole connector off. We do not carry any heavy coated wire, but we do carry wire loom that might make cutting a bit more difficult like part # 459075-1. The best solution for preventing cutting I could think of is using flexible...
    view full answer...

  • Do I Need to Install a 4 Flat Connector on my Motorhome with 5 Way Round
  • I recommend installing a 4 way flat like the Hopkins Endurance, # HM48030, on the back of your RV. This will allow you to plug directly into the Roadmaster Universal Wiring Kit, # RM-154. Since your RV is already wired for a trailer connector, you will not need to use the Roadmaster Brite-Lite Wiring Converter, # RM-732.
    view full answer...

  • Adapting a 7-Pin European 7-Way on 1999 Range Rover to US 4-Way Flat Trailer Connector
  • You would have the same problem using adapter # 118710 as you would with just splicing in a 4-Way. The adapter doesn't convert the separate signals to combined signals used by most trailers in the US. You would need to add a converter, # RM-732, which will take the separate signals and combine them. You could then wire in a 4-Way flat such as # HM48030 on the output side of the converter.
    view full answer...

Info for this part was:

Photos by:
Theodore B

Expert Research:
Michael L

Expert Research:
Reno H

At we provide the best information available about the products we sell. We take the quality of our information seriously so that you can get the right part the first time. Let us know if anything is missing or if you have any questions.

Stay Connected

Subscribe to email newsletter


privacy - we don't send unsolicited email

Free Shipping on Orders Over $99

Only 21 Hours 33 Minutes Remaining reviews

All images, layout and content copyright