Ford 3G 95-Amp Alternator, Rectifier & Regulator

Driven at roughly 2.8 times crankshaft speed by the serpentine belt is the Ford 3G (Third Generation) 95-amp alternator. Its ventilated cast-aluminum housings enclose a 12-pole spinning claw-pole rotor, twin internal cooling fans, a 3-phase copper-wound laminated stator, a 6-diode positive/negative heat-sink rectifier bridge, and an integral solid-state electronic voltage regulator with dual carbon slip-ring brushes.

Why Alternators Generate 3-Phase AC First: In an old DC generator, the heavy high-current windings had to spin on the rotor and pass 95 amps through sparking segmented commutator bars. An alternator flips that inside out: a small 3–5 amp DC field current enters the rotor through smooth copper slip rings to magnetize 12 interlocking north-and-south steel "claw poles." As those magnetic claws spin past the stationary 3-phase copper stator windings, they induce high-current three-phase alternating current directly in the stationary frame.

6-Diode Full-Wave Rectification & Field Regulation: Three positive silicon diodes and three negative diodes act as one-way electrical check valves, flipping every negative AC half-wave upward into smooth 14.2-volt DC output. To keep system voltage rock-steady whether you are idling with the headlights and blower on high or cruising at 3,000 RPM, the solid-state regulator rapidly switches rotor field current on and off hundreds of times per second.