Shrimper

Has anyone hooked up a auxiliary fuel tank without using the main tank on a 2006? I have custom built a 105 gallon tank for my 2006 Mega Cab 5.9 I just bought. I was planning on hooking up the tanks separately but found out that might not be possible. I have the 6 way valve and a extra 72 gallon an hour pump with an auxiliary fuel sending unit. I hooked up a setup just like this on my 03 and it works well. I made several calls and was told that if I set this truck up like this it will probably throw out several codes. 1- the fuel level will not go down fast enough showing that it's not using enough fuel. 2- The computer that runs the fuel pump might throw a code because it might realize that this is the wrong pump for this truck. The way that I hooked this up, the auxiliary pump will run on the same wire as the main pump. It should realize that a pump is running. 3- The auxiliary guage will hook up and work the OEM dash guage for fuel level. I would think that the gas guage wouldn't be a problem because it will use fuel maybe just not fast enough. I realize that most hookup are ran through the main tank. I Hope that this would work on this truck, but before I do this I need some input or someone that has tried this. Did this work or did it cause a bunch of code problems? Thanks For Any Input, Kyle Kimball

ataboy9026

The setup would work trouble free if you simply use the auxiliary pump you have to pump fuel into the main tank. That way ALL fuel is fed to the engine in the stock method. I did it to mine. Just cut the filler hose and install a tube with 2 ports, one for feeding fuel from auxiliary tank and 1 for the return back to the auxiliary. That way if you forget and leave the auxiliary pump on the fuel is fed back to the auxiliary tank. I put my switch down under my center console so that it has to be up in order to pump fuel, with that I rest my arm up on top of it as it pumps and it is out of my "normal" driving position. It takes a little while for the stock tank to be filled and its easy to forget with driving, radio playing, cell phone talk,etc. I also have a guage for the auxiliary tank mounted next to the switch. Here are pic's of mine...

Shrimper

I was planning on doing that, exactly what you did if the seperat system dosen't work. I wanted a separate system so if you have a fuel pump failure or any problems with the fuel you would always have a complete separate system. I have built several tanks and always hook them up separately. I am going to try to hook it up separately and see what happens? I have to make sure that the amp draw on the OEM fuel pump is the same as the auxiliary fuel pump. The Auxiliary fuel pump on my 03 draws 5.1 amps with the engine off and 4.5 amps with the engine running. You can hear the change on the pump when the engine is running. Thanks, Kyle

ceaman

several companies in northern indiana hook them up as seperate. My 115gal tank works fine, does set a code with no light for irrational fuel guage. its been like this for 300,000 miles. Im running a big holley black pump with no problems hooked up similar to your description

Sixpack73

you wont throw any codes based on a fuel pump with a different current draw. there are tons of us using aftermarket lift pumps that can attest to that. and as long as your fuel sender has the same ohm rating as the stock one, you shouldnt have any trouble there either.

Shrimper

OK it's all hooked up and I am useing a carter 72 gallon an hour pump. The amp draw on the OEM in tank fuel pump is 5.6 amps, the carter is drawing 3.6 amps. I cut the fuel line wire that feeds the in tank fuel pump and installed a 10 amp fuse on that wire for powering both of the pumps when the switch is fliped to tank 1 or tank 2 . Ths sending unit is 240ohms empty and 33ohms full, it reads corectlly on the OEM dash guage with both sending units.