Ford F650 fuel tanks not equalizing

Hopefully someone can help me out of a huge mystery here.
Ok I'm working on a 2007 f650 with a Cummins. The right side fuel tank is over filling, the electric transfer pump which is supposed to draw out of the left tank to keep both tanks equal, just keeps on pumping till the right tank over flows.
The only way it stops pumping is if the left tank level drops below 1/2, or if either tank is empty.
I've replaced the pump, the left sender, and right sender.
From the wiring diagrams I've looked at, I don't see what else is involved in making the decision to stop the pump.
I've ohmed the senders, I have power, ground, and required 7v to the pump.
Totally lost!

 

46520731 is the engine number. The wiring diagram I looked at was from the ford side out of a motor manual.

 

Ok I got a new piece of info from the customer. A couple months ago we had replaced the transfer pump because the right tank was not filling, well turned out that we had jumped the gun and it was just a blown fuse for the pump. Customer now says they've had this new problem ever since. So last week we put another pump on it thinking that was the problem, but it didn't change anything.
Is it possible the dealer is selling us the wrong pumps?

 

Problem solved. Our dealer sold us the wrong pump.