Fuel gage is NOT working on 2003 Aztek. Any ideas on how to proceed with a fix?

Professional scanner will sweep test gauges to determine where problem is!!... Any up to date repair shop should be able to do this test. ... No use guessing at what the problem is, that cost too much!!...As for the rest of you're question, it remains TBD!

Fuel level sending unit in fuel tank goes bad on this vehicle all the time. Most likely need to replace fuel pump with sending unit.