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. Charge line connects to the 6-way or 7-way plug on your vehicle. Requires separate charge line in RV.
Features:
Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.
Today, we're going be taking a look at the Roadmaster battery charge line kit for towed vehicles part #RM-156-25. One reason you may need this kit is if you plan on using a portable braking system in your towed vehicle, because those will draw power and they need some sort of power source. That way, if that's drawing power, you won't need to worry about your batter being drained because you've got a charge wire on here to make sure that your battery stays at full power. Here's what it's going to look like once it's installed on the vehicle. We've got the charge wire running to that very center pin on our six-round connector, here, to the circuit breaker underneath the hood. Then it goes out the other side of the circuit breaker and routes towards the jump post for the battery. Underneath this fuse box, here, at the jump post, you can see that it has a ring terminal that connects it there in order to get power to the battery when this vehicle is in tow mode.
Now with the vehicle hooked up to the motorhome, even with our ring terminal disconnected from the jump start terminal there, if we test it for power, you can see we've got power coming through there even when it's not. You know it's going to have power to help charge the vehicle when it's being towed. This kit does come with some split wire loom that is the same length as the wire provided in the kit, but we weren't able to use it on this one just because of how the wiring was routed. Now, let's show you how to install this charge wire kit. In this case, we'll be working on a 2016 Chevrolet Equinox. I started out by using a fish wire to route the wire that will come down here to our six-round connector and will plug into the back of it there.
I routed it up along the inside, here, to where it comes up behind this headlight and comes out right here. Now what I'll do is remove this plastic covering that comes all the way up along here. In order to do that, it's just got some pushpin fasteners. You can use a trim panel tool if you have one. If you don't, you can also use a flat head screwdriver for this, that works just fine.
You want to get the center of it popped out there, and then the body of it should come right out. On this plastic cover, there's going to be four of these pushpin fasteners. The last one is going to be up here by the strut tower. Once you've got those pushpin fasteners out, it's got this weatherstripping, here. It just clips on to the edge of it. It's got that little hook.
A little hole in the end of it, there, and you just need to unclip it. Then you can work your way down the side. It's got a couple clips that hold it in place. Now what I'm going to do is take our 15 amp circuit breaker, and I'm going to install that right down in here. I'm going to take the two self-tapping screws that come in the kit. Now what I can do is take my wire, pull it up so I have about the right length. I'm going to give myself just a little bit extra, and I'll clip the wire, there. Then I'll strip the end of this wire back, and install it in one of the smaller blue ring terminals that comes with the kit. Then I'll crimp that down. When you crimp that down, you want to make sure that it's a nice secure connection, it's not going to come out there. Slide it on to that copper post there. Take one of the nuts that came on the circuit breaker, reinstall it. Then I'll grab 3/8 socket in order to tighten that down. With the excess wire, I'll strip another end back, here, install the other small blue ring terminal onto the end of that. That one I can install onto the silver post and install the nut. With that red wire coming off the silver post, I routed that down here, and around our coolant reservoir, towards our fuse box, here. Now I'm going to take our fuse box off, and there's just a couple pinch tabs on either side in order to pull that off. Now what I'm going to do is use this little bit larger blue ring terminal and you connect it on to the end of my wire, here. I'm going to put it to where it's on the underside of this jump post here, this positive jump post. In order to do that, I need to remove that jump post. 10mm socket, put it on the top of it there, and it will thread off of there. Now I can take this wire with about the length I need, and I can install my larger blue ring terminal. With that on there securely, I can slide that down onto the post, there, and thread it back on. Now we can reinstall our fuse box cover. We can also reinstall our plastic paneling over here on the side. Now what we need to do is we need to take our six-round connector off so that we can install our charge wire into the back of it. It'll take 5/16 socket to take our self-tapping screws back out. Then we can pull this out so we've got some room to work. The first thing I'm going to do, pull that dust cover off. I'm going to take the red charge wire and feed it through that dust cover. Now what I'll do is I'll strip the end of that off. Then this charge wire will be going into that very center location that sticks out. I'll loosen the screw for that one, slide the charge wire in there, and tighten that screw back down to make sure that charge wire is nice and secure. I'll slide the dust cover back on there. Then I can reinstall my six-round connector to the mounting locations. That's going to complete our look at the Roadmaster battery charge line kit for towed vehicles, part #RM-156-25.
Average Customer Rating: 4.7 out of 5 stars (85 Customer Reviews)
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. Charge line connects to the 6-way or 7-way plug on your vehicle. Requires separate charge line in RV.The product was exactly what I needed to keep the battery of my towed vehicle charged and it was very easy to install.I would recommend it for everyone that has a motor home and a tow vehicle. 544210
I have a battery charger cable from my RV to the towed car. My battery is in the rear so the instructions state I can attach the wires to the battery connector points up front. But then it says to attach the charger thing as close to the battery as possible. Question - Do I put the charging thing in the rear or the front 582538
Mike L - 11/15/2018
I installed this baseplate on my 2003 Honda CRV myself. It was a challenge for an inexperienced mechanic but successful in spite of that. Following the clear instructions, the unit fit well into the CRV chassis. Installing it myself has also given me confidence in towing that I may not have had by giving that task to someone else. I wired the CRV and RV 6 way and 7 way connectors including power to charge the CRV's battery while towing. After towing the car for several thousand miles, I am very satisfied with the base plate, tow bar, and installation. 681269
Ordered 3 parts: RM-156-25; RM-156-75 and DW05745-10. All received very quickly, as is the case when I purchase from etrailer. More importantly, I get a 'live person' when I call for assistance and the service rep. is always knowledgable ( not an answering service that "will have someone call back". Time was spent with me answering all my questions and providing suggestions and opinions when I as for them, related to my project. Great company, great service - keep up the great work! 693892
this does not isolate your battery from feeding back into your motorhome, this is simple a circuit breaker with a piece of wire and connectors. if it was a real kit it should have a protective diode to insure issues in the towed vehicle do not interfere with the charging system in your motorhome, as it is this is just a jumper between the alternator/battery in the motorhome and the alternator/battery in your towed vehicle. 477658
OK...did the job, but kit should include diode block. 682693
So happy to have found this product. It will keep my Dinghy tow car battery charged up. The people at etrailer were very nice and helpful. 675094
I ordered all the parts required to safely flat tow out 2017 Jeep Cherokee Trailhawk from etrailer.com. The only part they didn't have was the Mopar Flat Tow Enhancement kit Jeep requires to flat tow this model. Ordering from them was great, the website is easy to use and I was able to locate all the pieces compatible with my specific vehicle. The expert recommendations help my decision choosing the right parts. I ordered from etrailer even though I found some of the parts on other websites a little cheaper. I chose to pay a little more because of all the effort etrailer has put into installation videos and guides. I was very pleasantly surprised to learn from etrailer that they have a price match guarantee! So my equipment consisted of the following Mopar Flat Tow Enhancement Kit (from Jeep) Roadmaster Battery Charge Line Kit for Towed Vehicles Mighty Cord 7-Way RV Style Trailer Connector - Trailer End WesBarg 7-Way, RV-Style Connector w/ 6' Long Coiled Cable Trailer End Pollak Black Plastic, 7-Pole, RV Blade-Style Trailer Socket - Vehicle End Hopkins Custom Tail Light Wiring Kit for Towed Vehicles SMI Stay-IN-Play DUO Supplemental Braking System Roadmaster Brake-Lite Relay Kit for Towed Vehicles Blue Ox Alpha Tow Bar - Motor Home Mount - 6,500 lbs Blue Ox Base Plate Kit - Removable Arms Blue Ox Tow Bar Cover - Aladdin, Aventa LX, Aventa II The installation videos are great but not all inclusive. Take the time to read the instructions that come with the parts. This is a major project, I took about 30 hrs over a full week but as you'll see in the pictures I took s few extra steps to make a cleaner look. Some of those extra steps: The base plate install requires the bumper be modified cutting off a flange on each side, I spray painted this to prevent corrosion. In the install video of the baseplate on the drivers side they use an extra quick link (not included) to run the safety cable around the wiper fluid reservoir. I took the time to remove it and run the safety cable behind it. I didn't want our nice new vehicle to look like it can be towed so I played the brake away switch and 7 way trailer plug behind the license plate, so when not being towed our vehicle looks great! Some things to be aware of. The Brake air cylinder that mounts to the brake pedal with four bolts may need longer bolts, it did on our Jeep. Spend the money for weather tight heat shrink crimp fittings. The Hopkins wire harness was about 1.5 feet short to get to my plug location. Buy extra zip ties, electrical tape and split loom. I recommend reading all the various installation manuals and watching all the videos because the various components integrate together and if you install one at a time you'll be doing a bunch of extra work. The brake light relay is a real pain in the butt, not because of the hardware but because of the location of the brake light switch which is very hard to get to. Overall I am very happy with the products and how the installation looks. We haven't towed it yet but do not expect any problems. 410271
Roy - 07/30/2018I bought and installed base plate and wiring on a 2018 Ford C-Max hybrid car. The wiring was a little complicated due to the hybrid setup on the car, however, everything worked out well. I have done this on several other cars I have towed behind my motorhomes. All products and help from etrailer.com was excellent. The video presentation was very helpful. 681635
All the products I ordered from etrailer,fit and worked excellent for me to be able to flat tow my 2015 Chevrolet Colorado behind our motorhome. I live in Canada and fast delivery on the products I ordered. I will order from etrailer again 819728
Haven't installed yet but the people at etrailer know their stuff and had my order shipped the same day. It's what you want when you need something fast 807990
The instruction video was the biggest help. Because I’m very visual without that I’m not sure I could’ve done this. It turned out great and I’ve not had any issues in the last year. 807683
Save my battery 802264
The kit was easy to install and works g reat!! 802194
This product solved my problem of when being towed my 2018b chevy equinox the battery would be dead if towing more than four hours . installed wiring kit problem solved. 796979
it works 792029
Great fast service! 790468
Works as promised i would advise to watch video first before install i read the instructions and switched up the wires on the circuit breaker watched the video and saw that i had Hooked up wrong all good now! 777929
Took under 15 minutes to install works great 777396
Great product installed very easily. 777387
This product works and does exactly what is says. I am 100% satisfied with my purchase. Recommended to any one who needs a battery charge line for their cutoff switch. 766042
Easy to install, can’t comment on its function as I’ve not used it yet, but I have no doubt it should serve the purpose. 764673
Shipping was fast and installation easy with no issues. Installed in 2019 Subaru 6sp Crosstrek. A must have when towing. Installation took about 1 hour. 764111
No problem. Works perfectly. 756630
The connectors worked great and the prompt delivers helped get my project to completion. 756204
Info for this part was:
At etrailer.com 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.
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.