I have a 03 Chevy Silverado 1500. It’s had trouble starting for a couple months, now it starts up and will die right afterwards every now and then. Sometimes it’ll idle rough at lights like it’s gonna die but never has. Headlights have been flickering for months and the gas guage doesn’t read correctly or at all. It also tells me I have low fuel when I have more than half a tank. Autozone says my alternator and battery are good. What else could it be? (It’s been taken through mud and creeks a few times)
Ground connections immediately come to mind. The battery negative cable at rhe chassis end. The strap to the engine, the ground wires on the frame immediately below the driver’s left foot will affect the instruments. Corrosion on the engine compartment fuse box underside as well. Get out your ohm-meter and start searching
A weak and failing fuel pump as well if it hasn’t been changed. A pressure test and a leakdown test of the fuel pressure would determine that.
Sounds to me like a new fuel pump and sending unit are in your future, unfortunately. They are a single combined unit in the fuel tank.
Budget about $700 for the repair. I’ve had to replace a few. Be grateful that you have some warning; sometimes they just stop one morning when you’re trying to get to work. Or already driving…