85 Chevy Truck Wiring Diagram | Chevrolet Truck V8 1981 85 Chevy Truck Wiring Diagram | Chevrolet Truck V8 1981-1987 Electrical Wiring Diagram. Projects to Try. What others are saying Search results for chevy truck diagrams free - Info 1985 Chevy Truck Chevy 4x4 Chevrolet Trucks Chevrolet Blazer 4x4 Trucks Truck Parts Wire Diagram Car Restoration. a Blazer/Jimmy/Bravada/s10 pickup/etc. analog instrument Look for the white connector taped to the harness. Find the solid white wire going into it. If you had a digital insturment cluster factory installed, this wire would pass through the connector and go to your instrument cluster. Cut into that wire and use some 16 or 18 gauge wire and route it to the instrument cluster connector.