Erratic Fuel Gauge - Fuel Sending Unit Cleaning and Refurbishment

Fuel gauge reading is erratic and inaccurate, moving slowly from Full to half then dropping rapidly from half to Empty

Dirty and corroded wiper arm contact surface and wire coil inside the fuel sending unit, with buildup of old dielectric grease and oxidation (greenish residue) causing inconsistent electrical resistance readings

Moderate confidence — Multiple community members agreed on this solution