What's the Purpose for the Aux fuel tank

cncsparky · May 25, 2013, 08:57 AM

What is the purpose of the second fuel tank? Is it for the generator only? The PO tried to get the generator running but couldn't get it to fire. I chased the fuel line back and it seems to go to the top of the main fuel tank. The smaller fuel tank has a hose also running to the top of the main tank. I'd have thought Hm? if the aux fuel tank was for the generator, the hose would go to it. There is also a momentary toggle on the dash labeled 'main'and Ã¡ux' , is that to switch between tanks or to check fuel level?

-Tom.

ibdilbert01 · May 25, 2013, 09:22 AM

The purpose is just so you can drive further without stopping for gas as much. Normally (at least on the older rigs) the generator is connected to the main tank, but on a short pickup tube. The idea of the short pickup tube is so you can't let your generator suck the tank dry and leave you stranded needing gas.

As for the dash switch, normally its to switch between the tanks and also switches over the fuel gauge. Some of the older units had two gas gauges and some of them even had manual cable valves. Were I'm confused on yours is the "momentary" toggle, I'm not sure of any valves that worked with a momentary toggle.

MotorPro · May 25, 2013, 10:04 AM

How much gas do you have in the main tank? Generator intake lines are set about 1/4 of the way up the tank so the generator will not suck you tank dry.

cncsparky · May 25, 2013, 10:35 AM

The main tank is nearly empty, I was hopeing I could put a couple of gallons in the aux tank to fire the generator.

MotorPro · May 25, 2013, 10:53 AM

Generators run off main tank

LJ-TJ · May 25, 2013, 12:22 PM

Just been there done that. The genny runs off the main tank as Dilber says. My main was almost empty so I filled it up and the genny fired right up. I'm not sure what you mean when you say you have a momentary switch on the dash. My one switch says "Main-Aux" that's for the two fuel tanks. When you say you have a momentary switch I think of the switch that says MOM on it and that's for checking the battery's.

JDxeper · May 25, 2013, 12:45 PM

I think he is referring to the infamous "MOM" switch which switches on both the coach and chassis battery to have extra power to start engine.

LJ-TJ · May 25, 2013, 01:00 PM

The tube on the right is the main pickup and the shorter one on the left is the generator fuel pickup tube. So you can see how the generator would only drain down your main fuel to a certain level and then stop before your hole tank went dry and why if your main tank isn't full why your generator wouldn't start.

cncsparky · May 25, 2013, 05:53 PM

Ok a little more info. The switch is momentary switch, normally in the down position, when pressed and released it goes back to the down position. I found an original brochure in my RV packet, it lists my coach as having standard equipment a 20 gallon Auxillary generator fuel tank. I would normally take this as meaning the aux tank only supplies the generator, if I had not chased the fuel lines underneath.