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  1. Tow Bar Wiring
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  3. Wiring Harness
  4. Plugs into Vehicle Wiring
  5. Custom
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Hopkins Custom Tail Light Wiring Kit for Towed Vehicles

Hopkins Custom Tail Light Wiring Kit for Towed Vehicles

Item # HM56205
Our Price: $60.44
You Save: 41%
Tow Bar Wiring

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Hopkins Custom Tow Bar Wiring - HM56205
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Wire your vehicle and get the signal lights required for flat towing without having to splice into your wiring with this custom, plug-in harness. Integrated diodes prevent feedback from RV for safe operation. Wires as combined lighting system. Great Prices for the best tow bar wiring from Hopkins. Hopkins Custom Tail Light Wiring Kit for Towed Vehicles part number HM56205 can be ordered online at or call 1-636-306-4830 for expert service.
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Hopkins Tow Bar Wiring - HM56205

  • Wiring Harness
  • Plugs into Vehicle Wiring
  • Custom
  • Tail Light Mount
  • Hopkins

Wire your vehicle and get the signal lights required for flat towing without having to splice into your wiring with this custom, plug-in harness. Integrated diodes prevent feedback from RV for safe operation. Wires as combined lighting system.


  • Lets you wire your vehicle to accept your RV's tail, brake, and turn signal lights for flat towing
    • Wires towed car as combined system so that brake and turn signals travel along same wire
    • Provides 4-way flat plug at front of towed car to connect to motor home
  • Plugs in quickly and easily - no cutting or splicing of wires
    • Connection points are located behind your vehicle's tail lights
  • Prevents electrical feedback to safeguard towed car's electrical system
    • Weatherproof box keeps built-in diodes protected
  • Won't interfere with electrical system when towed car is not hooked up to RV
  • Custom designed for your vehicle
  • Includes wiring harness, mounting bracket, and installation hardware
    • Extension loop for connecting towed car to RV is sold separately
    • Brake light relay (RM-88400 - sold separately) may be required if used with supplemental braking system
  • 90-Day warranty

Wiring Your Towed Car with Hopkins

Wiring your car for flat towing has never been easier. No more testing wires or splicing into your electrical system. No need to painstakingly position multiple diodes beneath your vehicle. No worries about voiding your warranty. With this custom-fit towed vehicle wiring kit from Hopkins, all you have to do is plug the harness into your vehicle's existing wiring, which is located behind your car's tail light assemblies. No cutting, tapping, or splicing is required.

After plugging in the wiring harness, use the included bracket to mount the 4-way flat connector at the front of your towed car. An extension loop (sold separately) is required to connect your towed car to your RV.

Changing from a Separate to a Combined Lighting System

Your vehicle ordinarily operates on a 3-wire system, wherein the brake signal and the turn signals travel along different wires to illuminate different lights. (Typically, this means that your vehicle will have amber turn signals.) This is referred to as a "separate lighting system." When you hook up for flat towing using this harness, however, your towed car's lighting system will operate in a combined fashion. This means that the brake and turn signals sent by your RV to your towed car will be carried on a single wire. As a result, your car's brake lights will do the flashing for the turn signals. Your vehicle will still function as designed - with separate lighting - when not hooked up to your RV.

Do You Need a Brake Light Relay?

Because this harness wires your vehicle as a combined system, a brake light relay (RM-88400 - sold separately) may be required if you use a supplemental braking system with your towing setup. A supplemental braking system depresses the brake pedal in your towed car every time you apply the brakes in your RV. So, if your towed car's brake lights illuminate when the brake pedal is pressed and the engine is off - as is the case when towing - then you need to install a relay to ensure that the lights on your towed car always act in accordance with the signals sent by your RV via the wiring harness. Without a relay, the brake signal from your towed car will override the turn signal sent by your RV when you slow down to make turns, creating a potential hazard.

11156205 Hopkins Plug-In Simple Dinghy Towing Harness

Replaces 56205

This Product Fits The Following Vehicles

California residents: click here

Video of Hopkins Custom Tail Light Wiring Kit for Towed Vehicles

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

Video Transcript for Hopkins Tail Light Wiring Kit Review

Hello neighbors, it's Brad here at etrailer, and today we're taking a look at the Hopkins plug and play diode wiring kit for your flat towed vehicle. Now, these are not available for all vehicles. There's a bunch of different vehicles that are able to be flat towed, and only a few of 'em have this wiring kit. But if your vehicle does fit into our fit guide, and this is a confirmed fit, you're in luck. Because this is truly just a plug and play, there's no cutting or splicing required. Go ahead and plug these in.

So pretty straightforward. It can only really go in one way. So we'll get this one popped in. Take the other connector plug here, plug that into the tail light. Now other diode kits are pretty straightforward, but there is cutting and splicing that needs to be done to the wiring on the taillight.

And a lot of these small taillight wires from the factory are pretty small and you're putting spade connectors on there and they do work well. But if you do have a loose connection, you may have faulty wiring, and there are quite a few points where you're gonna tie into those, and that's the glory of this kit. You can literally just plug this in, and it's gonna be a factory style connection, making it super easy. You don't have to worry if all of your crimps weren't done properly. Now with this kit, you are still gonna have to run wiring underneath your vehicle, and during that process you're gonna wanna make sure that you don't hit any exhaust, the suspension parts, or anything moving really, just, you want to keep that wiring nice and safe.

And following factory wire loom is generally a pretty safe route to get back to your plugs, and then up to the front. So your six pole is going to have your wiring up front and through the RM umbilical that's gonna transfer not only a 12 volt, so if you're using a charge line, but also your running lights, your brake lights, as well as your turn signals, and that's gonna keep you safe and legal. Now, diode wiring is a really nice thing to have if you plan on flat towing quite often. And that's because a lot of other vehicles that you see flat towed, you're gonna see some magnetic lights that are stuck here. And a lot of times you can get wireless ones, but sometimes you have to run a cable all the way to the RV.

And diode wiring is just nice, because when you plug in your umbilical, you not only can you send 12 volt power through there to a charge line if you want to, but also you're gonna mimic all the turn signals, running lights, and brake lights on the towed vehicle. Now diode wiring is gonna be part of the five main components required for flat towing your vehicle. So along with that, you also have your base plate, which is gonna be the attachment point on the front of your car, your tow bar, which you'll connect it to. You also have your safety cables here, just in case of an accidental disconnect. It's gonna hold that vehicle together, and also your braking system, which will have a breakaway switch allowing that vehicle to come to a stop if it does become disconnected. But also it's going to slow and stop the vehicle as you apply the brakes on the RV. When it comes to setting up your vehicle for a flat tow, we have plenty videos available on a variety of different cars. So using the fit guide on our website is gonna help you find those videos to make sure that you get your installation done. And we're always here to help. So if you need to, you can always give us a call, and we'll make sure that you're able to flat tow your vehicle. Now diode wiring is pretty common to go with the Roadmaster. That's what we see a lot of with our installs, and it's a great system. It's universal, so it works on pretty much every vehicle. But if your vehicle fits into the fit guide, having this Hopkins wiring, I highly suggest it. It's super easy and it just takes a little bit of headache and guesswork out of splicing into wires. This one, plug and play, ready to go. So if this is an option for your vehicle, I highly suggest it..

Customer Satisfaction Score:

Customer Reviews

Hopkins Custom Tail Light Wiring Kit for Towed Vehicles - HM56205

Average Customer Rating:  5.0 out of 5 stars   (3 Customer Reviews)

Wire your vehicle and get the signal lights required for flat towing without having to splice into your wiring with this custom, plug-in harness. Integrated diodes prevent feedback from RV for safe operation. Wires as combined lighting system.


Great product easy install, works great.




See what our Experts say about this Hopkins Tow Bar Wiring

  • Custom Tow Bar Wiring Harness for Flat Towing 2008 Jeep Commander Behind Motorhome
    For your 2008 Jeep Commander, the Hopkins Custom Tail Light Wiring Kit for Towed Vehicles, part # HM56205 is what you are looking for. This harness easily plugs into your vehicle's existing wiring, located behind your Jeep's tail light assemblies. No cutting, tapping, or splicing is required. If your motorhome uses a standard 7-way connector, you can use coiled adapter # 787196 to connect to the 4-Way on # HM56205. With this harness hooked up for flat towing, your Jeep's lighting system...
    view full answer...

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Info for this part was:

Employee Leah B
Edited by:
Leah B
Employee Lindsey S
Written by:
Lindsey S
Employee Dustin K
Video by:
Dustin K
Employee Chris R
Video Edited:
Chris R
Employee Wilson B
Updated by:
Wilson B
Employee Alexander C
Updated by:
Alexander C
Employee Bradley B
Installed by:
Bradley B

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