Troubleshooting Aux Fuel Valve Connections

[Redcrew71]

Have a 71 f250. has the longer inside frame aux fuel tank with the valve besides drivers seat valve and the under dash fuel gauge switch.

It has been running on Aux. my gauges done work. (I am working on that more below). I notice that under truck one side of the 3 way valve is disconnected. Wondering if this means
a) my cab tank is disconnected?
b) the Aux tank may be plumbed direct to motor & the valve is not used.

fuel5.JPG

The one on the bottom is coming down from cab tank above.
In grounding out the sending unit wire my cab tank goes to full. Where is the aux tank sending unit located on the tank...can one reach it by taking the steel cover off the tank? front back top?

Thanks

[cdnwillyg]

On my aux tank the sending unit is right by the U-joint facing the center of the truck. No need to take anything off.

[colnago]

From the photo, it looks like your valve is not connected to your fuel pump. Your inside tank, yes, but the other ends of the valve aren't going anywhere.

Joseph

[Redcrew71]

From the photo, it looks like your valve is not connected to your fuel pump. Your inside tank, yes, but the other ends of the valve aren't going anywhere.

Joseph

me thinking that the valve is totally bypassed and the previous owner just ran the back tank direct to fuel pump

[basketcase0302]

me thinking that the valve is totally bypassed and the previous owner just ran the back tank direct to fuel pump

From your picture your right-the dual tank valve is not doing anything and your probably running off of the rear tank, (the looped rubber tubing in your pic).

[colnago]

The good news is that this probably means your aux tank is clean and solid. It should be really easy to plumb everything back correctly. Or, you can leave it as-is, remove the main tank from the cab, and have a bit more storage room behind the seat.

Joseph