bing tracking image
  1. Accessories and Parts
  2. Roadmaster
  3. Tow Bar Wiring
  4. Adapters
  5. 7 Round - Blade to 6 Round
  6. Coiled Cord
Roadmaster 7-Wire to 6-Wire Flexo-Coil Kit

Roadmaster 7-Wire to 6-Wire Flexo-Coil Kit

Item # RM-146-7
Our Price: $82.95
You Save: 14%
Accessories and Parts
Orders above $99 qualify for Free Shipping
Shipping Weight: 3 lbs
In Stock
zoom in icon
slider vertical icon
zoom out icon
Comment field cannot be left empty.
Name field cannot be left empty.

Thank you! Your comment has been submitted successfully. You should be able to view your question/comment here within a few days.

Error submitting comment. Please try again momentarily.

Product Images

In Use/Installed

Customer Photos

Need help with installation?
Locate installers near me
Easily and effectively connect your motor home to your towed vehicle with this water, oil, and chemical-resistant electrical cord. Flexo-Coil technology allows cord to extend more than 8' and then contract conveniently for storage. 1-800-940-8924 to order Roadmaster accessories and parts part number RM-146-7 or order online at Free expert support on all Roadmaster products. Great prices and Fastest Shipping for Roadmaster 7-Wire to 6-Wire Flexo-Coil Kit. Accessories and Parts reviews from real customers.
  • All Info
  • Reviews (183)
  • Q & A (0)
  • Videos (18)
  • Photos
  • Why etrailer?

Roadmaster Accessories and Parts - RM-146-7

  • Tow Bar Wiring
  • Adapters
  • 7 Round - Blade to 6 Round
  • Roadmaster
  • Coiled Cord

Easily and effectively connect your motor home to your towed vehicle with this water, oil, and chemical-resistant electrical cord. Flexo-Coil technology allows cord to extend more than 8' and then contract conveniently for storage.


  • Adapter cord can be used for multiple towing applications
    • Perfect for running power from your RV with the 7-pole, round plug to your towed vehicle or trailer with a 6-pole, round plug
  • Flexo-Coil cord can expand more than 8' yet still contract to prevent dragging and tangling
  • Silicone-injected plugs prevent corrosion
  • Electrical cord is resistant to water, oil, and chemicals
  • Center pin on 6-Way plug wired to 12V power for RM-146-7, there are two industry standards
  • Assembled in the USA

Notes: Flexo-Coil cords are not intended for use with Roadmaster All Terrain tow bars or any other tow bar that includes cable channel guides. Only straight cords should be used with those models.

146-7 RoadMaster 7-Wire to 6-Wire Flexo-Coil Kit

Video of Roadmaster 7-Wire to 6-Wire Flexo-Coil Kit

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

Video Transcript for Roadmaster Flexo-Coil Kit Installation - 2018 Chevrolet Colorado

Speaker 1: Today on our 2018 Chevrolet Colorado we're going to be taking a look at and showing you how to install the Roadmaster seven wire to six wire flexo coil kit, part number RM-146-7. We have our cable router along our tow bar here. As you can see the coiledness of it is going to keep it nice and taut. We won't have to worry about it dragging the ground, but it is extendable up to past eight feet, so we're going to have plenty of room to make our connections.So we'll dust cover off of the back, and we're going to slide the wires through it. Let's go ahead and push it back so we have plenty of room to work with. Now, if we look at the back our plug here, each one of these terminals is going to be labeled.

If you look really close we follow starting from the top that would be labeled TM, that's for your trailer marker or your tail light circuit. If we move going counterclockwise, the next one is going to be labeled GD for ground, LT for left turn, RT for right turn, and then the two leftover. You're going to have an S, and the center one is going to be labeled A. Typically the center one is going to be your auxiliary power circuit, and the S is going to be for your trailer brakes. However, we're only going to be using the four since we only have four fold flat trailer connector.We're going to need to separate each one of these wires, just enough so we have room to work with.

Take a pair of cutters, we're going to go right in between each one of the wires. You want to be careful not to damage the wire itself, and pull them apart. Strip back a little bit of insulation off of each one of the wires. Grab our plug, we're going to grab a screwdriver, you'll use a small Philip's screwdriver to loosen up one of the terminals. We're starting on the top, so we're going to take our brown wire, since that's our taillight circuit.

We're going to slide the bare wire into the terminal, then we won't have to worry about connection issues, so we know we have a solid connection. We'll tighten up the set screw, make sure the wire's securely in there. Then we're going to work our way around until we have all the wires in the appropriate terminals.Loosen up our ground one, this will be our white wire. Then we'll just repeat the same thing of tightening it down, and we'll work our way across. With all the wires attached take a little bit of dial electric grease, and fill the entire cavity up.

This is going to help prevent any kind of moisture from getting inside. Hopefully prevent any type of corrosion from building up. You need some dial electric grease you can pick some up at take our dust cover and slide it back over the back of our connector. Then to help keep in place, and also again to help keep out that moisture, I'm going to wrap the entire dust cover and a little bit of the wire here in electrical tape. It'll help hold everything in place, keep all that debris from getting inside, and also hide those wires a little bit, instead of having those bright colored wires on the front of our truck.You can take our plug, we're going to push it through the bracket. Then in our kit they're going to provide us with some screws and lock nuts. So we'll just line up the holes in our socket, going through the front. We'll take our lock nut, and for now just loosely put it on hand tight, so we can get both of them in.I'm going to take a three ace wrench. I'm going to hold the nut on the back side while I tighten up that screw. Now with the plug mounted we can go ahead and put our facial back in place. So now we can take our chord and plug it in to our socket on the truck. You're going to make sure you get it all the way in, so it's not going to come out. Now we're going to hook it up to our tester to make sure our lights are working properly.If I turn on my tester to simulate the lights on my motor home. We can see that my taillights are going to come on. As well as my left turn signal, my brake lights, and my right turn signal. Even though we didn't mess with our factory wiring or the lights themselves we can see that our lights are going to work normally when we're driving our truck around, and we're not hooked up. That will finish up your look at the Roadmaster seven wire to six wire flexo coil kit part number RM-146-7 on our 2018 Chevrolet Colorado.

Customer Satisfaction Score:

Customer Reviews

Roadmaster 7-Wire to 6-Wire Flexo-Coil Kit - RM-146-7

Average Customer Rating:  4.9 out of 5 stars   (183 Customer Reviews)

Easily and effectively connect your motor home to your towed vehicle with this water, oil, and chemical-resistant electrical cord. Flexo-Coil technology allows cord to extend more than 8' and then contract conveniently for storage.


Vehicle; 2019 Chevy Equinox 2.0 liter Turbo AWD
I purchased the following parts from etrailer and installed them myself as per the instructions provided with the parts. The Roadmaster parts provided by etrailer are the best quality and there service is second to none.
Parts purchased;
RM-156-25 & RM-156-75 Battery charge kit.
RM-523193-3 EZ4 Base kit.
RM-751489 Stop light switch kit.
RM-98160 Brake master air brake kit.
RM-146-7 Power cord
Thank you etrailer for your great service & product support.

Since I installed these parts we have towed the Equinox about 20000 miles and havent had any problems with any of the products. They work exceptionally well. Very Happy
Rob K - 12/16/2020


Had a safety pin come out [of the truck receiver] and cable broke, my mistake. not strong enough otherwise very pleased

Just fine. Breakaway cables should be stronger. bought different vehicle to tow and a new road master kit It took 2 mechanics 3 days to install 2022 Jeep. $xxxx. GRRRRR
Allan - 12/18/2022


Wired up the 6 wire receptacle in place of the flat 4 plug and mounted to the base plate. Looks great. Checked that wires from MH match this for proper operation.

Has worked flawlessly. Very pleased!
J J - 04/08/2020


Well made product. Have ordered a number of products and have never been disappointed. The service is excellent, all those I spoke with were knowledgeable and helpful. I would recommend anyone needing a setup to tow a vehicle behind an rv go to etrailer, outstanding company!


Product Review:
This is my second set
of this kit. Setting up another TOAD. Very easy to install. Nice screw terminals with big enough holes for appropriate cable gauges. Everything you need is included. Even nuts/bolts.
Yes, I could have just ordered the receptacle for my second TOAD, but having a second cable as a spare is not such a bad idea ;)

Site Review: E-trailer is super easy to navigate. Easy to check out via CC or paypal...and you get follow up emails. No chasing after tracking numbers or order status' ... All diagrams and product data is available. If it isn't they'll get it for you ASAP. Top notch service IMO.


Shipped very quickly, good quality prod uct!


Just what the RV doctor prescribed, and it arrived 2 days early!


Appears to be a well made piece of equipment that should last a long time. Good price and as always expert assistance in selecting the right item for the job. Took a little longer than usual to get it (7 days) but I will put that on the USPS.

works fine, no issues.Fair price and fast delivery.
Robert F - 03/14/2022


This is a must have to connect your "toad" to your motorhome. It works very nicely with the Blue Ox Tow Bar Wiring Kit with 4 Diodes.

Highly recommened.

Its working out great
Dale H - 06/14/2021


Great products!!!


This marches my broke cable exactly and was sent to me quickly. Thanks for your good service.


The 7 to 6 coiled cable from came the next day and is exactly as described. After having ordered the same item from another professional online hitch-seller in Texas, paying for the item, and waiting 3 weeks without even a thank you for your order or status of the order, I finally had to call and leave a voicemail, then call back the next day to find out the order might ship on Friday. Needless to say I cancelled the order and called and spoke to Jan at who handled my order and verified each item was in stock and would ship the next day. Boy was I surprised when the driver delivered my package at noon the next day. A real Professional company. Buy with confidence.

Perfectly. I always know the the electrical connection between the Motorhome and the towed vehicle will function as designed whenever I hook the two together.
Ed R - 01/30/2015


Works great, easy to install!


Still kept up to setup and connections. Great so far.


Has worked just as promised. It has worn well and looks to last a long time.

It has worked just as it should. Is still in great condition.
Keith A - 03/18/2022


Good quality and works very well.


Everything you need to install!!


Easy to use, works well at 40’!


Ashley was wonderful to work with and she was able to answer all my questions on electrical cord.


The 6 wire connecter is exstremely hard to plug in. might have to put some grease on it.

by: is a great place to shop. I experienced fast shipments and received orders were accurate. These products were just some of the products that I purchased for towing a 2014 Jeep Compass. I also purchased a Blue Ox Aventa LX tow bar and baseplate!


Works exactly as expected, the connectors both ends were tight because of the new plugs very good product..


The connector did not want to plug into the towed vehicle receiver. After an hour or so of trying I was finally able to make it work by squeezing each pin together to make them a bit smaller so the go into the receiver.


You get what you pay for, I paid for quality and that's what I got. This plug has not failed me yet, it was exactly the plug I needed to operate the towed vehicle brakes and additional line for battery charge while towing. Great product and I must say all the videos on etrailer are top notch quality and very helpful.


Works great! Can't beat etrailer fast delivery. Had to change receiver female socket on RV to position above hitch bar as kept bending on driveway. Nothing to do with this product though.

Show More Reviews

See what our Experts say about this Roadmaster Accessories and Parts

  • Wire Gauges Used for RoadMaster 7-Wire to 6-Wire Flexo-Coil Kit
    You are correct. The wires for the light functions in Roadmaster Flexo-Coil Kit # RM-146-7 are 16 gauge and the 12 volt power and ground wires are the larger 14 gauge. I have linked a video review of this product for you.
    view full answer...
  • Does the Battery Have to be Disconnected to Flat Tow a 2015 Chevy Suburban Behind a Motor Home
    The battery should be disconnected because your 2015 Chevy Suburban has some feature that draws power when the vehicle key is in the towing position indicated in the owner's manual. If you leave the battery connected then what will happen is the battery will drain unless you stop frequently enough to let the Suburban motor run so the alternator can charge the battery back up. But there is a way to provide a maintenance charge to the vehicle battery when flat towing it with the battery...
    view full answer...
  • Location for Installing Tow Lighting Socket on a 2016 GMC Canyon
    I attached a picture of a 2016 GMC Canyon front end that has a tow bar lighting socket installed in the front grille right above the license plate. That would be a great place to install the # RM-146-7.
    view full answer...
    Image 1 for
  • Durability and Compatibility of Roadmaster 7-Wire to 6-Wire Flexo-Coil Kit
    Roadmaster over-builds their products and we have not heard of any issues with coiled extension kit # RM-146-7 so I believe that you will like it and that it will last a good long while. The 6-Way connector in the kit will fit Blue Ox base plates. If it is a snug fit or off just a little you can get a deep well socket to gently bend the posts on the base plate.
    view full answer...
  • What Gauge Wires are Used in the Roadmaster 7-Wire to 6-Wire Adapter # RM-146-7
    I spoke to my contact at Roadmaster and he informed me that the gauge wires that are in the RoadMaster 7-Wire to 6-Wire Flexo-Coil Kit # RM-146-7 are 14 gauge and 16 gauge.
    view full answer...
  • How To Wire 6-Way Socket On Roadmaster 7-Wire to 6-Wire Flexo-Coil Kit
    I have attached for you below a diagram of how to wire the vehicle side plug on the Roadmaster 7-Wire to 6-Wire Flexo-Coil Kit part # RM-146-7. That said, you must know the function of each wire which can be found with a circuit tester, you cannot simply color match in all cases.
    view full answer...
    Image 1 for
  • Replacement Adapter Wiring For Mopar Flat Towing Harness On a 2019 Jeep Wrangler
    I do have one suggestion as we do not carry that Mopar specific harness. I recommend the Roadmaster 7-Wire to 6-Wire Flexo-Coil Kit # RM-146-7. For me this is a better route to go as the connections will be much easier attached and removed from your 2019 Jeep Wrangler Unlimited when you are setting it up for towing or removing it from tow. The coiled electrical cable will also allow for the wiring to sit higher while towing and will be less likely to drag on the ground and become damaged....
    view full answer...
    Image 1 for
  • Where is RoadMaster 7-Wire to 6-Wire Flexo-Coil Kit Assembled
    It is likely the RoadMaster 7-Wire to 6-Wire Flexo-Coil Kit # RM-146-7 was assembled in the USA with components coming in from elsewhere. This is something that is pretty common to save consumers money; parts are sourced elsewhere but assembled in the U.S.
    view full answer...
  • Replacement Cable For Roadmaster Sterling Tow Bar
    The RoadMaster 7-Wire to 6-Wire Flexo-Coil Kit # RM-146-7 can expand to over 8 feet. It keeps coiled shorter for compact storage and to keep from dragging while in use. If you are looking to run the cable through a tow bar channel, I recommend the Roadmaster 7-Wire to 6-Wire Straight Cord Kit - 6-1/2" Long # RM-98146-7 which is 78 inches long but can be trimmed to length.
    view full answer...
  • Availability of 6 Pin to 7 Pin Adapter
    There a couple adapters which might work for you, the Hopkins # 47435 6-Pole to 7-Pole or the RoadMaster # RM-146-7. I've left links to video reviews of both adapters for you to take a look at.
    view full answer...
  • Can Battery on 2015 GMC Terrain be Charged While Flat Towing it Behind a Motor Home
    Check the owners manual for the vehicle you intend to flat tow because you may or may not have to disconnect the battery to flat tow it. If you do not then it is possible that there is some feature that could drain the battery while in tow. And of course if you do have to disconnect the battery it would not drain. To provide a maintenance charge to the vehicle while in tow you would attach a charge wire to the battery and connect it to the Terrain side connector. I recommend using a 6-way...
    view full answer...
  • Replacement Coiled Section for Roadmaster Diode 7-Wire to 6-Wire Flexo-Coil Wiring Kit
    In order to replace the umbilical cord on the Roadmaster Diode 7-Wire to 6-Wire Flexo-Coil Wiring Kit part # RM-15267 you'll need the Roadmaster 7-Wire to 6-Wire Flexo-Coil Kit part # RM-146-7. It does however come with new mounting brackets as well.
    view full answer...
  • Brake Controller Port and Connector for a 2017 Tiffin Allegro Red
    To install the a brake monitor light on your 2017 Tiffin Allegro Red you will want to use the brake controller port that will be to the left of the steering wheel under the dash. The actual part number for that connector from Freightliner is PAC 12064754. This part should work for all Freightliner Chassis from 2004 to 2017. The connector is a 6 wire connector with a cap on it. I attached a photo showing it with the cap in place and removed. There are 5 wires going into the back of the...
    view full answer...
    Image 1 for
  • Tow Bar Wiring Recommendation for Roadmaster All-Terrain Tow Bars
    For the all terrain tow bars the non-coiled wires are recommended since the arms telescope and the all-terrain bars come with guides. But if you really wanted to use the # RM-146-7 with an all-terrain bar you can technically still do it. A better recommendation would be the # RM-98146-7 as this is a straight cord. However, I attached a picture that shows the # RM-146-7 being used with the Falcon 2 Tow Bar part # RM-520 which is an all-terrain tow bar.
    view full answer...
    Image 1 for
  • Is A Battery Disconnect Needed for a 2015 Jeep Wrangler To Prevent Dead Battery
    There isn't a battery disconnect required for the 2015 Jeep Wrangler. If it was required, it would state this in the owner's manual. In regards to the key position this would be listed in the flat-tow setup procedure for your vehicle which is in the owner's manual. I would not have any additional information outside of this. That said, the battery going dead is an easy fix as all you need to do is install a charge line between the motorhome and toad using the Roadmaster Battery Charge Line...
    view full answer...
  • How To Run a Battery Charge Line on 2019 Ford Ranger for Flat-Towing
    In order to charge the battery on a 2019 Ford Ranger while in tow I recommend the Roadmaster Battery Charge Line Kit for Towed Vehicles part # RM-156-25. The connection can then be bridged with the Roadmaster 7-Wire to 6-Wire Flexo-Coil Kit part # RM-146-7. This is by far the best option, all you need to do is install a 6-way on the vehicle which is provided and then you don't have to make any additional connections each time you get setup. I don't have any good options for a dedicated...
    view full answer...
  • Flat Towing 7-Way cord That Will Add Charge Line to 2009 Jeep Wrangler
    You need the Roadmaster 7-Wire to 6-Wire Flexo-Coil Kit # RM-146-7. It will have you cut off your 4-Way on the Jeep and wire in a 6-Way receptacle to give you an additional charge line circuit for your 2009 Jeep Wrangler. It is a better wiring connection as well as the 6-Way has a stronger connection that won't pull from the socket when towing. The entire cord is coiled to keep from dragging while towing as well. I recommend Battery Charge Line Kit # RM-156-25. It utilizes a circuit breaker...
    view full answer...
  • 2017 Ford F-150 Towed Change 4 pole to 7
    I recommend using the Roadmaster 7-Wire to 6-Wire Flexo-Coil Kit # RM-146-7, simply cut off your current 4-Way and rewire with the 6-Way to provide the charge line for your towed using the Battery Charge Line Kit # RM-156-25. The Kit allows up to 15 amps from your RV's battery to be used to maintain the charge of your towed car's battery while the car is being towed. This Includes 14-guage wire, split wire loom, circuit breaker, and hardware. The kit is made in the USA.
    view full answer...
    Image 1 for
  • How to Keep 2017 Chevy Spark Battery From Dying While Flat Towing
    You, my friend, need the Roadmaster Battery Charge Line Kit for Towed Vehicles # RM-156-25. This connects the battery on your 2017 Chevy Spark to the umbilical at the front of your vehicle so you'll pull 12V power from your motorhome to keep the battery charged. If you don't have a 6-Way on your Chevy Spark then you can upgrade your wiring with the Flexo-Coil Wiring Kit # RM-146-7. Attached is a photo of the pinout for the 6-Way socket. I've also linked an installation video of this kit...
    view full answer...
    Image 1 for
  • Does the LED Bulb and Socket Tail Light Wiring Kit Pull Power Directly from Motorhome
    That is correct. The LED bulbs for the Tail Light Wiring Kit # RM-152-LED will install into the tail light housing on your 2019 Chevy Equinox and then you'll route the 4-wire harness to the front of the vehicle and install it in a plug like what comes with the Flexo-Coil Kit # RM-146-7 so they receive power directly from the motorhome. For a complete flat towing setup you will need a base plate kit, tow bar, safety cables, vehicle tow bar wiring, a supplemental braking system, and possibly...
    view full answer...
  • Correct Tow Bar Wiring for a 2022 Jeep Gladiator Mojave with LED Tail Lights
    For your 2022 Jeep Gladiator you need the Roadmaster Wiring Kit with Smart Diodes for Variable Voltage LED Tail Lights # RM47ZR as well as the 7-Wire to 6-Wire Flexo-Coil Kit # RM-146-7. This is designed around the LED lights on your Mojave so everything will continue to work properly. Unfortunately there aren't any plug-in options that tee in behind the tail lights of your vehicle. Attached are some videos for you to check out.
    view full answer...
  • Maintaining Battery in Vehicle Being Flat Towed Behind RV
    First, you will need to confirm that the vehicle is suitable for flat towing. From what I have read on page # 319 through 321 of the owners manual, your GC can be flat towed if the transfer case has a Neutral position. If your 7-way on your RV has a 12-volt power feed (typically the pin in the 1:00 position), you can use that circuit to maintain your battery, however it will not charge a discharged battery. We offer a Flexo Coil Umbilical kit, part # RM-146-7 that would work well for...
    view full answer...
  • Which Coiled Adapter # RM-146-7 Vs. Demco # DM9523054 Has Less Tension at 7 Feet
    The Roadmaster part # RM-146-7 would be longer than the Demco part # DM9523054 that you referenced. The Roadmaster is listed as having an extended length of up to 8 feet whereas the Demco is 7 feet so at 7 feet the Roadmaster would have less tension.
    view full answer...
  • How to Use Hopkins Magnetic Tow Lights With Power Wire For Supplemental Braking System
    While we have a solution for you to use your Hopkins Magnetic Tow Lights # C6304 and use the 7-way on your motorhome as the 12 volt power for your braking system, there isn't an adapter that offers a 7-way or 6-way as well as a 4-way. So what you would need to do is cut off the 4-way end of the lights and wire them into the 6-way connector of the Roadmaster 7-Wire to 6-Wire Flexo-Coil Kit # RM-146-7.
    view full answer...

< Previous
123. . .6

Do you have a question about this Accessories and Part?

  • Why

    At we guarantee:
  • Real product know-how.

    We make sure that the products we sell are what we say they are, and that they work the way they are supposed to work. Get real advice from a real person who has the knowledge and expertise needed to solve your problem.
  • Most detailed, accurate accessories and part information available.

    Because we take providing accurate product information seriously, we take our own detailed product photos, demo videos and installation videos, as well as verify measurements, instructions, and vehicle fit information.
  • Installations, made easy.

    We love helping people and have the most highly-trained customer service, hands-on experience, step by step videos and installation instructions.
  • Fast shipping.

    Your order is automatically routed to get out of our warehouse and to your door as quickly as possible. Receive free shipping on orders over $99.
  • Personalized service for life.

    We provide one-on-one, personalized service from the ordering process through the life of your product.
  • Trusted since 1946.

    We've been serving customers since our parts store first opened in 1946 and continue to be recognized by our customers, our vendors and third parties for exceptional service.
  • Returns Policy

    Need to return an item? No problem. Please read our Returns Policy for more information.

Info for this part was:

Employee Joe V
Test Fit:
Joe V
Employee Nicholas E
Test Fit:
Nicholas E
Employee Shane T
Test Fit:
Shane T
Employee Randy B
Test Fit:
Randy B
Employee Andrew S
Test Fit:
Andrew S
Employee Brent H
Test Fit:
Brent H
Employee Robert C
Test Fit:
Robert C
Employee David F
Test Fit:
David F
Employee Zack K
Video Edited:
Zack K
Employee Joshua S
Video Edited:
Joshua S
Employee Jacob T
Video Edited:
Jacob T
Employee Chris R
Video Edited:
Chris R
Employee Andrew K
Video by:
Andrew K
Employee Andrew L
Video by:
Andrew L
Employee Kathleen M
Video by:
Kathleen M
Employee Alan C
Video by:
Alan C
Employee Jonathan Y
Video by:
Jonathan Y
Employee Michael B
Video by:
Michael B
Employee Michael H
Expert Research:
Michael H
Employee Jameson C
Expert Research:
Jameson C
Employee Jeffrey L
Expert Research:
Jeffrey L
Employee Matthew E
Updated by:
Matthew E
Employee Noah M
Updated by:
Noah M

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.

Product Experts Available Now!
Call 1-800-940-8924