Ford: The 1-wire alternator, which is ideal for a clean setup and simple installation, the 3-wire OEM-style replacement, or the earlier externally regulated alternator.
The Best Ford Alternator Options
The 1-wire alternator simplifies installation and provides a tidy configuration. It has a single wire that links the charge terminal to the battery or a 12V power source. These will be self-regulating and grounded during the block. A warning light cannot be connected to a 1-wire alternator, but most bespoke applications function well with a voltage gauge in its place. The cut-in speed (the speed at which the regulator starts charging) will be slightly greater (1200rpm or higher) than on typical alternators, indicating that they do not charge at idle.
A 3-wire or “OEM-style” alternator will also be internally regulated, with a charge post and two side terminals (viewed from the back). One terminal is often utilized for the field or exciter circuit, while the other is for the sensor circuit. They are significantly more difficult to wire but offer the benefit of charging at lower rpm and the ability to use an original warning light.
Externally Controlled Alternator
These earlier alternators might be classified as 2-wire, 3-wire, or even 4-wire. The crucial distinction, regardless of the nomenclature, is that they are intended to work with an external regulator. From the mid-1960s until roughly 1985, when Ford launched an internally regulated unit, they were used after generators were phased out. Original Autolite models (1964-’71) had rounded corners on the casings, and when Ford converted to Motorcraft around 1972, they also designed a handy Y-shaped connector with caps for the connections. The newer Tuff Stuff unit displayed is rated at 70 amps, as opposed to the earlier units’ 38-55 amps.