Demco 4-Diode Universal Towed Vehicle Wiring Kit

Demco 4-Diode Universal Towed Vehicle Wiring Kit

Item # DM9523010

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Tow Bar Wiring

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Tow Bar Wiring DM9523010 - Diode Kit - Demco
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In Use/Installed

  • Diode Kit
  • Splices into Vehicle Wiring
  • Demco
  • Universal
  • Tail Light Mount
Diode kit lets you wire your vehicle to accept the brake and turn signals from your RV for flat towing, all while preventing feedback from your RV. Wires 2-wire and 3-wire systems to operate as a combined lighting system. Lowest Prices for the best tow bar wiring from Demco. Demco 4-Diode Universal Towed Vehicle Wiring Kit part number DM9523010 can be ordered online at or call 800-298-8924 for expert service.

  • All Info
  • Q & A (2)
  • Videos (2)
  • Photos
  • Why etrailer?

Demco Tow Bar Wiring - DM9523010

Diode kit lets you wire your vehicle to accept the brake and turn signals from your RV for flat towing, all while preventing feedback from your RV. Wires 2-wire and 3-wire systems to operate as a 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
  • Prevents electrical feedback and the damage it can cause to your vehicle's electrical components
  • Heat-sealed casing protects diodes from the elements
  • Includes:
    • 4-Wire harness
    • 4 Diodes
    • 12 Wire connectors
    • 4 Quick-splice wire connectors
    • 6 Nylon ties
    • 1 Ring terminal
  • Made in the USA


  • Wiring harness length: 26'
    • Wire gauge: 16
  • Max voltage: 24 volts
  • 1-Year warranty

Note: For applications that have separate lighting, this kit will cause your brake lights to function as both brake and turn signal lights. A wiring converter (118158 - sold separately) and 2 additional diodes will be needed if you want to retain separate turn and brake signals.

Separate vs. Combined Lighting Systems

Some automobiles operate on a 3-wire system, wherein the brake signal and the turn signals travel along different wires to illuminate different lights. (Typically, these vehicles have amber turn signals.) This is referred to as a "separate lighting system." When you hook up for flat towing using this kit, your towed car's lighting system will operate in a combined fashion regardless of whether it typically has combined or separate lighting. 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 when not hooked up to your RV.

Do You Need a Brake Light Relay?

Because this kit wires your vehicle as a combined system, a brake light relay (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.

9523010 Demco RV Taillight Wiring Kit

DM9523010 Installation InstructionsInstallation Details DM9523010 Installation instructions

This Product Fits The Following Vehicles

1998 - 1998 Mazda Miata

Video of Demco 4-Diode Universal Towed Vehicle Wiring Kit

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

Video Transcript for Demco Tow Bar Wiring - Splices into Vehicle Wiring - DM9523010 Review

Speaker 1: Today we're going to take a look at the Demco tail light wiring kit with diodes. This kit will allow your motor home or RV to power the lights on your towed vehicle without electrical feedback. It uses the heat-sealed diodes to connect your towed vehicle's brake, running, and turn signal lights and the diodes are designed to protect both vehicles' electrical systems by preventing backflow of electrical feedback.This part will include everything shown here, the four heat-sealed diodes, 26 feet of four conductor 16 gauge wire with the four way flat connectors on each end, butt connectors, wire splicers, ring terminal, even some nylon ties to take up any slack in the wiring, and a nice detailed wiring instructions on how to install it. But that should do it for the review on the Demco tail light wiring kit with diodes.


Ask the Experts about this Demco Tow Bar Wiring

Do you have a question about this Tow Bar Wiring?

  • Tow Bar, Wiring, and Base Plates Compatible with 2019 Jeep JL Rubicon with Stock LED Tail Lights
  • The Demco Kwik-Tow Tow Bar - Car Mount - Adjustable Width Arms - 2" Ball - 5,000 lbs # DM9511011 you asked about is compatible with your 2019 Jeep JL Rubicon as long as you don't overload it. The curb weight is 4,439 based on my research but if you load it up with cargo it could easily exceed the tow bar capacity. The vehicle capacity is 5,800 lbs. If you are careful, that tow bar will work for you. My recommendation is to use a tow bar with greater capacity like the Roadmaster...
    view full answer...

  • Parts Needed to Flat-Tow a 1980 Jeep CJ-7
  • Due to the age of your 1980 Jeep CJ-7, I was not able to find any information in regards to flat-towing. You will need to look in your owner's manual to confirm the proper flat-towing producedes assuming it is allowed. If it is allowed you will need a tow bar, base plate kit, safety cables, flat-tow wiring, supplemental braking system, and ball mount/hitch ball. I have attached my recommendations on each of the following for you. Tow Bar: Demco Kwik Tow Tow Bar part # DM9511011 Base...
    view full answer...

Do you have a question about this Tow Bar Wiring?

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Info for this part was:

Edited by:
Lindsey S
Installed by:
Jeff D
Video Edited:
Joshua S
Video by:
Chris R
Video by:
Jonathan Y
Test Fit:
Robert C
Updated by:
Hannah L
Test Fit:
David F
Written by:
Kristina F

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