Community Forums

RicB · 01-12-2025, 11:43 AM

I am installing a charge line for my towed vehicle. Do I need to use a diode to prevent feedback from the towed vehicle to the coach? The 12v feed from my coach is constant hot.

Chargerman · 01-12-2025, 12:12 PM

Nope

Dutch Star Don · 01-12-2025, 12:41 PM

Rather than just run a line, it's worth it to use one of the premade units. I use the one linked below. It's fused and protected. It's already to go, just attach the unit near your battery and connect the wires. If you have an unused lead in your umbilical, it will make for a clean setup.

Once installed, start the coach, pull the fuse and put a voltmeter on the incoming side of the fuse holder. If you have 12 volts, you're ready to go.

https://www.etrailer.com/Accessories...5f9a995b0c6cf8

https://a.co/d/4Kk0eWD

Steve-W · 01-12-2025, 04:01 PM

If your coach has a constant hot to the 7 pin vs ignition controlled. you either should install a diode in line or disconnect the 7 pin when your parked. If you leave the 7 pin connected the coach may draw down the battery in your toad.

Roadmaster makes a diode that is great for this purpose or you can use a properly rated diode of your choice.

twinboat · 01-12-2025, 05:03 PM

If the hot wire is not switched, buy a Bosch type relay and make it switched. Diodes have a voltage drop across them.

ArtJoyce · 01-12-2025, 06:20 PM

I'm sure somebody does a diod, but i never knew anyone who did. The most common is to install an auto reseting fuse link for the amp rating of the wire size.

US1 · 01-12-2025, 09:17 PM

No, you do not NEED a diode. A reason they are installed, is without a diode, there will be 12V to the round 6 way plug at the front of your car even when not connected to the RV. With a diode, you will not have have 12v at that plug when not plugged in. With 12v at that plug, there can be a problem of corrosion developing inside the plug since its a high chance of rain water being its located at the front of your vehicle. Its not a sealed connector.

dvspl · 01-13-2025, 09:18 AM

I think a diode or relay in the charge line is probably the most elegant solution. The charge line needs a fuse, too, but that doesn't prevent the coach battery from drawing power from the toad when it isn't running. In my case, I just disconnect the umbilical when I'm parked for more than a couple of hours with the coach not running.