Dual tanks: switch/valve question

I have dual tanks on my CJ5.

The valve for switching between tanks is located right in front of the front tank (under the drivers seat).

It has a pivoting arm for switching from tank to tank... the arm has a long side and a short stub side.

I can turn the long side of the arm 180 degrees... looks like it has 3 possible positions: 1) pointed all the way toward the passangers seat 2) pointed toward the front of the vehicle and 3) pointed toward the drivers side door.

Right now it is pointed toward the passanger side, and it seems to draw gas fine, but I'm not sure which tank it's drawing from (everything is together, and I don't want to pull it apart to 'test).

So any ideas which tank it's drawing from, and which positions draw from which tanks?

Thanks

 

depends on how it is plumbed
only sure way is to pull hose/valve and visually inspect
which is open and which is closed and when according to the handle.
you can plumb them so the arrow points opposite of which tank your on
one of the three positions should be an off as well; not bad idea to use when you park the Jeep, theft deterrent
one tip: when you pull the hose off, gas in the armpit BURNS !!!!