Running a 12v Line to Flat Tow Vehicle

[BillSpin]

My 2000 Adventurer only has a 6 pin hookup to flat tow with, it does not have a 12v line to maintain tow vehicle.

I need to run a 12v line to the rear of the rv, do I connect directly off my Driving battery?

[Our ride]

Originally Posted by BillSpin

My 2000 Adventurer only has a 6 pin hookup to flat tow with, it does not have a 12v line to maintain tow vehicle.

I need to run a 12v line to the rear of the rv, do I connect directly off my Driving battery?

You can,just make sure you have a circuit breaker/fuse at the battery. I would run a wire from both the positive and negative posts (2 separate wires ) to the rear of the rv.Makes it easier to hook up to the vehicle battery that is being towed.

[BillSpin]

Thanks, what size fuse would be appropriate for the line?

[Our ride]

Originally Posted by BillSpin

Thanks, what size fuse would be appropriate for the line?

15/20 amp on positive wire would be sufficient

[Ray,IN]

Change to a Bargman 7 connector connection, it does have a 12V+ connection., plus you eliminate the loose pin connections in that old style round split pin.

[bigb]

I don't understand why the 6 pin won't work. The only difference is the 7 pin has an extra "aux" pin in the center which is sometimes used for reverse lights.
The 6 pin has everything you need and is easily convertible from your TV 7 pin. The only thing I had to do to mine was install a fuse for the 12 volt power as my TV was shipped with the fuse slot empty. I even used the blue "brake" pin wire to back feed a brake light indicator LED on my dash as I am not using a trailer brake controller.

[Ray,IN]

Brian, the Bargman 7-blade connections are under spring tension, while the round pins are simply split to allow them to be pried open to make solid contact. This is a common problem_lack of a good solid contact.

[powercat_ras]

On my 2015 Winnebago on Ford F53 they feed chassis battery to the rear connector thru a 12 gauge wire that is 20 amp fused. On my towed vehicle I have a 15 amp auto reset circuit breaker between the Ford Escape battery and the 6 pin connector. You need protection on both ends in case something fails in between.

[bigb]

Originally Posted by Ray,IN

Brian, the Bargman 7-blade connections are under spring tension, while the round pins are simply split to allow them to be pried open to make solid contact. This is a common problem_lack of a good solid contact.

OK I see. I hope my 6 pin holds out, that was a lot of work to set up initially and an expensive 7 to 6 umbilical.

[Ray,IN]

Originally Posted by bigb

OK I see. I hope my 6 pin holds out, that was a lot of work to set up initially and an expensive 7 to 6 umbilical.

As long as it's working stay with it; my umbilical cord is 7-blade Bargman to a Blue Ox 5-pin and it's been working for 10 years so far. I just had to open the pin slots once, so far.

[k9jkfham]

Roadmaster makes 12 volt line kit. Easy to install. Sold many places about $30 to $35. I used on my vista and works great

[dnrainey]

Hi, I'm just curious as to why you need a 12V circuit to "maintain" your tow vehicle? You don't mention what you are towing. The only reason I have heard where you need a 12 V line from the MH might be if you are having to use a pump to circulate fluid in the tow vehicle's transmission. Thanks, David.

[dgarrison]

Facing the same issue, we went to a local uhaul store and purchased a split wire bulb line 6 pin. Plugged it in the 6 pin, placed the wire under the hood front, then out at the front windshield, ran the wire to the back seat into the trunk, popped out the empty bulb plug, replaced each with the bulb on the split wire.Then tested the brakes, lights and 4Ways. Works perfectly. When we arrive, it's a simple reverse process.
I tow a 1996 BMW convertible, 12V, manual transmission, with our previous 04 Horizon, and our 2015 Ellipse 42QD, use Blue Ox.

I continue to use this method because the electronic theft system on the BMW will not allow any tampering with the wiring. To do so causes the theft system to activate. Ask me how I learned.....

I can also suggest a tail light system I purchased for additional illumination (the BMW can dissappear behind the Ellipse due to low height).

Magnetic tail lights, with Bluetooth transmission to sender unit placed on the hood of the BMW and connected to electrical plug at the rear of the RV.
Amazon or Campingworld even Walmart about $100.

Happy Trails...Deborah

[k9jkfham]

Not sure if U R asking me or Billzspin. For me I tow 19 equinox. It uses more battery when towing than most cars. Also my supplement braking system is attached to battery.

[ldfeat]

I have the 7 pin plug and the pin at the 1 O'clock position on the RV plug is connected to the coach battery, which is charged from the RV alternator. I made made sure I connected that same circuit to the positive terminal on my toad battery. You can verify which pin on your RV 6 pin plug by starting the engine on the RV and check which pin is reading 13+ volts with a simple meter. Then connect your toad cord to the rv and verify the 13+ volts is available at the other end of that cord/plug that connects into your toad plug. Find the 13+ volt wire at the back of the toad plug and attach it to your toad battery positive terminal. Now, with the RV engine running (preferably fast idle, 1000 RPM), connect your meter wire leads to the toad battery (toad engine off) and verify you have13+ volts which means the RV engine is charging your toad battery. Good luck! Larry 2014 Reyo P

[Morich]

So many times, this seems to get into a runaway situation where it gets way too far out in the bushes to make sense!
People just miss the basic idea that the RV is actually pretty well designed to be used as an RV, so they go way off track to do things that are not needed. That often gets into running way too many wires and using way too big as they don't understand the basics.

You need a good ground? The whole frame IS the ground, so you don't need to go all the way to the battery to get a good ground, just use what the rest of the RV uses and that is the frame! But first thought might be to use the ground pin in the connector??

The wire size doesn't need to be huge! Look at the sizes used on the connections and they are not set for 15 amps, in many cases. The point a lot miss on the wire size is that we are not planning to charge a totally dead battery if we drive the toad to the RV and hook it up. Can't we assume the toad battery is near or above 12.8 if we just drove it up there?
Can't we agree that the wiring we are adding is only meant to KEEP that battery charged as the toad uses some?
Look at OHM's law and remember the current is based on the DIFFERENCE between two points! As we drive, the RV may be at near 13-14 volts and the toad may be near 12.8, so the difference is only 2 volts or less. That means we are not putting much current into the toad battery but just replacing what is used!
If you don't drag the toad down the road with the lights, radio, and air running, that is not a big drain and the normal size wire is good to handle that!

Basic idea is to give the folks who build these things credit for knowing what they are doing??? Too many try to build a better mouse trap without knowing what a mouse looks like!