The presumption that all you need to do is switch tank pump power and control return fuel is in theory correct, but dead wrong in practice.
And "dead" is the operative word.
I have TWO check valves inline with the output of each tank, because I had
issues that an aircraft engineer would call "uncommanded crossfeed" where the inlet check valve built into the fuel pump failed on one occasion and the short length of hose inside the tank failed on another occasion.
In either case THE primary rule of multiple tank fuel systems is that fuel MUST return to the tank it came from, because in that tank there will be room for it... a "Crossfeed"
sends fuel to a tank that might not be empty... and infact might be full!
Understand that it takes a bit more than an hour for your fuel pump to pump the entire volume of fuel in the tank around the "loop", while in that time the engine will only burn 3-4 gallons of it... if it's crossfeeding to another full tank that remaining volume will be on the ground behind you... that unless it finds a source of ignition....
thus my "dead" comment...
Can I explain it step-by-step? sure I can... will I? Not likely... atleast not all at once....
I can't type the way I used to I suffered some nerve damage in my right arm
when I injured my shoulder this past winter and I literlally have to watch my
fingers while I type.
you need to know and deeply understand why you must not do certain things.
My goal was to maximize fuel capacity and a 20gallon plastic tank beats a metal 13gallon tank in both ways that matter.
My 1987 truck wears a plastic midship fuel tank as well... My supercab originally had a 14.5gallon metal tank midships, it has a plastic 22gallon tank now...
(that required hand made fuel lines, adding a crossmember that no 1988 or earlier has)
replacing another crossmember and modifying a third...
The rear tank REQUIRED a 1" body lift, modifying one of the deck support members in the underside of the bed and hand made crossmembers to hang it from.
I could show you in an hour or two wiuth a floor jack and a flashlight.
I can't type the way I used to I suffered some nerve damage in my right arm
when I injured my shoulder this past winter and I literlally have to watch my
fingers while I type... and my shoulder, arm and hand hurt most of the time.
AD