Roadmaster Diode 7-Wire to 4-Wire Flexo-Coil Wiring Kit
Item # RM-15247
Our Price: $144.46
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2005 GMC Sierra
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2005 GMC Sierra - Roadmaster Diode 7-Wire to 4-Wire Flexo-Coil Wiring Kit
- Diode Kit
- Splices into Vehicle Wiring
- Tail Light Mount
- Universal
- Roadmaster
Diode kit allows you to use your GMC Sierra's tail lights and wiring system while preventing feedback from your RV. Wires 2-wire and 3-wire systems to operate as a combined lighting systems. Includes 7-wire to 4-wire Flexo-Coil electrical cord.
Features:
- 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
- Diodes powder coated aluminum case is corrosion resistant and provides protection from the elements
- Brake light relay (RM-88400 - sold separately) may be required if used with supplemental braking system
- Flexo-Coil cord is resitant to water, oil, chemicals, and has silicone-injected plugs to prevent corrosion
- Includes: 4 Hy-Power diodes; 30' long, 4-wire harness; wire connectors; cable ties; 1 ring terminal; 3' long plastic loom, 8 ft coiled cord, vehicle mounting bracket, and socket
- Made in the USA
- Limited Lifetime Warranty
Specs:
- Diode Max amperage: 85 amps
- Diode Max voltage: 24 volts
- Coiled cord max length: 8'
- Coiled cord retracted length: 15"
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 (RM-792) 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 (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.
15247 Road Master Towed Car 4 Diodes RV Plug to 4-Wire Socket Flexo Coil Wiring Kit
Installation Details
Customer Satisfaction Score:
91% were satisfied with this product
9% of customers were not satisfied
- Wrong item was ordered
- etrailer mistake
- Product did not meet expectations
Customer Reviews
Roadmaster Diode 7-Wire to 4-Wire Flexo-Coil Wiring Kit - RM-15247
Average Customer Rating: 4.7 out of 5 stars (127 Customer Reviews)
Diode kit allows you to use your vehicle's tail lights and wiring system while preventing feedback from your RV. Wires 2-wire and 3-wire systems to operate as a combined lighting systems. Includes 7-wire to 4-wire Flexo-Coil electrical cord.by: James 03/27/2024
This place is the best! Placed my order- easy peasy-delivered on time-
Watched install video- again made it so easy and saved $1000 installation fee!!! Thanks for being a great company and special thanks to Carol C my order specialist !!!
by: Gregory 09/06/2022
I installed this myself along with a tow bar from another company at the same time, in about 4 hours. installation was straightforward and worked perfectly. saved about $800 in total labor.
by: Luke04/10/2024
1996 Ford F-250 and F-350
They work as the should.
by: Michael11/06/2023
Excellent quality and engineering. Installation requires a fair amount of mechanical sense and ability.
by: Randy07/07/2023
Not happy with the wiring kit. It didn’t work for my application. It was a good thing that I’m good with electrical because I had to make my own for my application.
by: William07/31/2023
Easy install, just mount it, run the wire to the break operator, plug it in and you’re good to go!
by: Robert 01/24/2024
No oroblem
by: Steve06/29/2023
2017 Ford F-250 Super Duty
The 7wire to 4 wire had a short in it I ended up just using an old one I had.
by: Bath11/26/2023
Rapid delivery. Works as expected.
by: Bill12/23/2022
Very easy to install and love that it doesn't interfere with our vehicle's lighting system. Was even easier to do the installation since etrailer has a step-by-step video for our vehicle year and model.
by: Richard C07/29/2022
It would have been 5 stars but the battery charge kit would not work with the 7 wire to 4 wire flexo coil kit, so I had to put together my own 7 wire to 6 wire harness to make things work.
Jenny N.
8/5/2022
I am glad that you were able to make it work. Since the 7 to 4 way Flexo coil kit comes with the 4 round plug it does not have enough connectors to attach the charge line kit to it. As you mentioned, you would need a 7 to 6 connector to allow it to work. You could go with part # RM-152-98146-7 which is a straight line kit or part # RM-152-1676-7 which is a hybrid straight line and coil kit. Since you already have part # RM-15247 then you can simply replace the 4 round connector to a six round connector with part # RM-910030-7 or part # RM-910030-5.
by: Robert10/19/2021
Little pricey for what you get. Needed to buy additional wiring to complete. The wiring that comes in the kit is no long enough to run from the tail lights to the connector at the front of the truck. Didn't use the flex coil wiring kit as I have a roadmaster nighthawk.
Jenny N.
10/22/2021
The bonded four wire that comes with the kit is 30 feet long. The installation manual advises to run the wire along the frame rail under the vehicle being careful to route it away from heat sources. You can see an install on a 2016 Ford 150 truck in the link below. I know it is not the same as your truck however the installation will be similar.
by: Jeffrey 10/13/2023
Great service
by: Tim Dahl, Pahrump, Nv.04/24/2022
Ford Ranger
Perfect Fit. I watched the video's that etrailer provides and decided to take on the install myself. Everything from the base plates, diode wiring kit, drop receiver and Blue Ox Tow bar went just as the video's showed.
We are very happy with the service and parts etrailer.com has provided us for our 2022 Ford Ranger.
by: George05/03/2022
Removed the wiring after the main computer module on the car failed shortly after installing it. Coincidence? Maybe. But I wasn’t going to take any chances.
Katrina B.
5/27/2022
I have gotten in touch with the manufacturer and they have said that the complication could be from not installing the diodes correctly. Did you use a brake light switch kit? If not, then the Roadmaster Diode 7-wire to 4-wire Flexo-coil Wiring kit will not work properly. If you do not have a brake light switch, then we recommend using a custom fit brake light switch # RM-751455.
by: Gary P11/19/2018
2015 Ford C-Max
I used this kit on a 2015 Ford C-Max Energi. All in all the installation kit was complete except it was missing the self tapping screw. This was not a problem since I was able to attach the ground wire to an existing ground connection without having to use the screw. It also did not have any screws (2) to attach the socket bracket to the baseplate (I used a Blue Ox BX2639 baseplate). Luckily I had a couple laying around. The hardest part was routing the wire harness throughout the undercarriage of the vehicle. I used almost all the wire ties for this part of the installation. I also had to purchase additional wire to run across the rear of the vehicle ( I needed additional green wire for the right side brake and directional and brown to jump to the other side for the parking lights. The directions provided in the kit were helpful but I relied quite a bit on the installation videos you provided. I found the videos provided much more detail and guidance.
by: Christopher 05/26/2020
2012 Jeep Liberty
This looks like a good quality lighting kit and was easy to install on my 2012 Jeep Liberty.
Christopher D.
5/27/2021
Still working great!
by: Gary S.07/21/2017
2014 Jeep Grand Cherokee
As you can see, I ordered the components necessary to allow me to flat tow my Jeep Grand Cherokee behind my motorhome. I followed the recommendations made by one of your employees as far which components would be necessary to meet my objective. Now that I have utilized this equipment to tow our vehicle over two separate trips to Seattle, Washington and also to Tucson, Arizona, I can report that we have been very satisfied with every aspect of our purchase. Thank you, again, for the expert assistance!
by: Mark Jensen07/15/2019
2005 Jeep TJ
Never flat towed before, enlisted etrailers help on what to get. Just returned from a 4000 mi trip to the northwest ! Had no problems towing a 2005 Jeep lj behind my motor home. Thank you etrailer for your assistance and great videos! Installed the system myself! Very happy!
by: Everything You Need05/18/2022
1995 Jeep YJ
I installed this on my 1995 Jeep YJ. After watching the video a couple of times, to get an idea of what I was getting myself into, this job was fairly simple. It took me about 4 hours total time, and when I plugged the wiring harness into my truck and all the brake & taillights worked perfectly on the Jeep.
by: Michael07/23/2018
2009 GMCSierra
etrailer has been fantastic to work with...email traffic after the sale was timely and informative as to when my items would ship, when they would arrive and then follow up if I was satisfied...this wiring kit assembly was easy to install...I utilized the provided directions and videos provided on this site and others...happy with the service, happy with the product, will order again
by: Dana04/19/2017
One major draw back that is see is that none of the wire connector spades you crimp on the end of the wires were of the Heat Shrink type. This leaves the wire exposed to water and possible corrosion. Need to spend the extra $$$'s and upgrade the spade connectors to the Heat Shrink type.
by: Kenneth04/07/2018
2018 Jeep JL Wrangler Unlimited
Easy install. This is my second wiring kit I have installed and with both, I only wish that an additional four or five feet of wire was supplied. Both times, I had to butt connect a couple of wires to get across from one tail light to the other.
by: Gary11/27/2021
Installation instructions were complete and helpful. No problem one year later.
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Show More Reviews
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Gregory V.
9/6/2023
Perfect no issues, I am very happy with the harness, I would buy this again if I change vehicles.