Ford 3G Alternator Wiring Diagram - Mega Fuse, Charge Lamp & Wire Colors

This document is a color-coded wiring diagram for a Ford 3G alternator charging system. It shows the alternator's internal components, the stator, rectifier (diode bridge), and voltage regulator with its 'sensing and switching circuits' and field winding, and how the unit connects to the vehicle's electrical system. The alternator B+ output feeds through a MEGA FUSE (no amp rating shown) via a red wire to the battery positive terminal. Three regulator-side connections are labeled: the S (stator) terminal uses a White/Black (W/BK) wire, the A (sense) terminal uses a Yellow/White (Y/W) wire routed to the battery-side circuit, and the I (indicator) terminal uses a Light Green/Red (LG/R) wire that runs to an optional instrument cluster charge lamp (with a 510-ohm resistor in parallel) fed by a 20A 'Hot in Run' fuse. A reader can learn the correct wire colors, terminal identifications (B+, A, S, I), fusing arrangement, and the charge-lamp/resistor circuit needed when installing or troubleshooting a 3G alternator, such as during the popular 3G alternator upgrade on older Ford trucks. The diagram carries a 2005 copyright watermark but does not state a specific model year, model, or engine applicability.