2005 chevy uplander fuel tank

SOURCE: fuel gauge moves back and forth from full to empty

you have a bad sending unit inside your tank.
the resistance of the potentiometer inside is broke on the half tank part.

you have to replace it.

tnx 4 using fixya.

drcool

SOURCE: I have a 1997 Chevy Blazer LS, the fuel gauge

all later model chevy vehicles are plagued with this problem it,s the fuel level sensor mounted on the fuel pump module inside fuel tank unfortunately on some models it,s only available with purchase of whole new fuel pump module that can run as much as $500.00 dollars for just the module not including labor to drop fuel tank and replace I encourage you not to waste time and money with aftermarket less expensive pump module assemblies not to knock any parts people but our shop just installed the 3rd napa fuel pump module in a 98 blazer because the new pump will not read correct amount of fuel finally it was replaced by a pump module assemblie from dealership at cost of $458.00 for pump it now reads correct hope this helps if you need more detailed instructions on how to replace repost at fix ya thanks