Both fuel pumps are powered by the fuel pump relay but ensure there is voltage at the fuel pump connector anyway, before replacing the fuel pump. There is a 95% chance it is the fuel pump going out on those systems but you can never be too careful, rats get hungry too.
Be lucky the check valve hasn't went bad where one pump pumps all the fuel into the other tank and vice versa, that happened to my dad's truck. If I had to drop the fuel tank again, I would probably cut out a access panel with oxy/acy torch so it wouldn't have to be dropped ever again. That is, when every last drop of fuel has been eradicated completely, first!