RepairPal Certified shops can diagnose and repair your 1999 Chevrolet Silverado 1500. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
The sender in the tank may be bad, the fuel gauge or the wiring in between. Sometimes it's just a dirty level sensor, try using some Chevron Techron in the tank see if it helps clean the fuel level sensor.