Dual fuel tank help please

[rwolf9653]

My grandfather has a 1987 V10 with the 305 and it cut out on him the other day. Now it will turn over, but not start. I spent a little time looking at it today and it is not getting fuel to the throttle body. I can hear a fuel pump run when it is on LEFT tank, but no pump noise when on RIGHT tank. I pulled the fuel filter and turned the key to the "ON" position and heard the pump run but no fuel came from the lines (left tank only, I tried right but no pump noise). I have not worked on the dual tank setup at all so can anyone explain this to me please?

Is there only one pump, or two?
There is only one fuel filter so I am assuming one tank pumps into the other? Left to right maybe?
It looks like the right tank is the main tank that feeds the throttle body, so if that pump quits there will be no fuel regardless of the LEFT pump working?

Any info is much appreciated. I hope to get the parts and make another trip down there to fix it, but he is two hours away so I would like to have what I need before I go.