Products to Compare (max of 3)
Compare These Parts

Ford Alternator Buying Guide

Add Article To List
Tags: Tech, Ford

When you start to look for an alternator, be it a simple aftermarket replacement, or a heavy duty performance unit, start your search at Speedway Motors. We offer three main types of alternators for your Ford: The 1-wire, which is great choice for a clean setup and easy installation, the 3-wire OEM-style replacement, or the earlier externally regulated alternator.


The 1-wire alternator offers a simplified installation and clean setup. It has one wire that connects the charge terminal directly to the battery or a 12V source. These will be internally regulated and ground through the block. 1-wire alternators will not have a way to hook up a warning light, but most custom applications work well with a voltage gauge in its place. The cut in speed (the speed at which the regulator begins to charge) will be slightly higher (1200rpm or higher) than most alternators which means they do not charge at idle.


A 3-wire or “OEM-style” alternator will also be internally regulated and have a charge post and two terminals on the side (viewed from back). Typically one terminal is for the field or exciter circuit and the rother terminal is used for the sensing circuit. They are slightly more complicated to wire up, but have the advantage of charging at lower rpm and the ability to use an original warning light.

Externally Regulated

These older style alternators can be referred to as a 2-wire, 3-wire, or even 4-wire. Regardless of the name, the important difference is that they are designed to work with an external regulator. They were used after generators were phased out from the mid 60’s until around 1985, when Ford introduced an internally regulated unit. Original Autolite models (1964-'71) had rounded corners on the cases, and when Ford switched to Motorcraft in about 1972, they also devised a convenient Y-shaped plug with caps for the connections. The newer Tuff Stuff unit shown is rated at 70 amps, compared to the 38-55 amps of original units.

Products Featured in this Article

Related Articles

1946 Ford Sedan Delivery-Employee Rides: Jeff Karls
by Jeff Karls - Posted in Tech
Ride along as you read the story of how "Looney Tunes" started and made its way back to the original owner after nearly three decades.
Simple Guide to Improve the Handling of Your Vehicle
by Darrian Wedding - Posted in Tech
Darrian gives a step-by-step guide on replacing worn steering components to improve the handling of your vehicle.
Understanding Shelby/Arning Drop Changes
by Darrian Wedding - Posted in Tech
Darrian explains the process of Shelby/Arning drop changes and how that affects your car.
Boxing Stamped Steel Control Arms
by Darrian Wedding - Posted in Tech
Learn how to fabricate stamped steel boxed control A arms . This process increases the rigidity of control arms while also reducing flex for peak performance.
Vintage Air SureFit Air Conditioning Kit Installation - 1965 Mustang
by Alanna Crawford - Posted in Tech
Learn about the installation process for a Vintage Air SureFit Air Condtioning Kit. Alanna C. walks you through as she installs the A/C kit in her 65 Mustang.
A/C 101 on a '65 Mustang
by Alanna Crawford - Posted in Tech
Speedway Motors employee Alanna C. walks through the how-to of installing the Vintage Air A/C in her 1965 Ford Mustang.
Vintage Air in a 1965 Mustang
by Alanna Crawford - Posted in Tech
Speedway Motors employee Alanna C. talks about the process of tearing down her 1965 Ford Mustang to make room for the Vintage Air A/C kit.
1946 Ford Sedan Delivery Engine Detail
by Jeff Karls - Posted in Tech
Speedway Motors Product Manager Jeff K. talks about how to really make your engine bay stand out from the crowd with just a little patience, and some Speedway products.
Putting a 32 Radiator in a 29 Roadster
by Tim Matthews - Posted in Tech
Tim talks about the process of adapting a full size 1932 Ford Radiator to fit in his 1929 Ford Roadster project.
Installing a F1 Steering Box In A Roadster
by Tim Matthews - Posted in Tech
Our Tech Expert installs an F1 steering box in his roadster to give the steering a traditional feeling. Follow his process from testing fit to welding.