Fuel not transferring between tanks on ProStar

[Pro Star Cummins]

We jumpered 12volt at pump. Both sending units had continuity check out
Ok .a float inside sending unit tube can get stuck or gummed up. I think
Right side only reads fuel level in that tank. The left side unit calls for
Transfer pump to operate when fuel level drops in left tank. The body
Control module is involved in this procedure also. I think you need to
Replace left side sending unit. We unplugged right side tank and put
150ohm resistor in it to get feed back to gauge ,gauge worked.
Also check for pinched hose or clogged breather vent.