I received and installed both the aux tank/toolbox combo and the hitch adapter yesterday.
The aux tank is a gravity based unit that is intended to feed from the bottom of the tank directly into the fuel filler neck. I used that configuration on my old truck, but decided to modify it a bit on the new one. I ordered various fittings, a filter, a small 12V pump and solenoid. The solenoid I received was the wrong one, but after some testing it turns out the pump will not flow anything unless it is on, so it acts as one. Perfect.
I had to cut into the factory filler neck and install a tee. Unlike GM, Ram uses a metal filler neck with little working room so this was more of a task than anticipated. I ended up getting away with only one cut since the neck already fits into a boot at one end, and I made that cut using a raw hacksaw blade because I couldn’t fit the entire saw in there. I drilled a 3/4″ hole through the side of the bed to run the line from the tank through. This approach worked out fairly well because I was able to avoid getting debris into the fuel tank by cutting with the filler neck completely disconnected from the tank.
I plumbed the gravity feed at the bottom of the tank through the included ball valve, up into a hole I drilled in the back of the toolbox, and into the pump. Then I ran the pump output back out of the shroud and into a fuel filter/ water separator which I mounted on the side of the box. The output of the filter then runs into the tee in the filler neck. I added an external vent for the tank, which you can see sticking out the side.
This truck came with six upfitter switches. I decided to use Aux 1 to power the pump through an inline 5A fuse.
When I push the Aux 1 button, power is provided to the pump and the fuel is pulled from the aux tank, pushed through a filter, and then into the main tank. Since this is only a 2A pump I didn’t use a relay. It took about 10 minutes to go from half a tank to 3/4 tank watching the factory fuel gauge last night. Since there is no automatic cutoff and I removed the restrictive check valve (ball) from the tee included with the installation kit, there is a risk of overflowing if I don’t keep an eye on it while filling – but as far as I know, that is the only downside to this approach. I really like the flexibility of it and the fact that I’m able to properly filter the fuel and separate water from it before moving it to the main tank.
The hitch dropped in with little adjustment and should be ready to tow with.