Hi Brett!
Try this: The sketch shows right pump and sender active.
When I want to change tanks (pump and sender unit) I flick the swith to the other position and the relay picks up. This will get the other pump going and it will change fuel sender as well. [img]images/icons/wink.gif[/img]
There are a number of ways to solve this. This is one of the simplest sollutions. I use a similar scheme in my car and it works perfectly.