Wiring Up a Ford G Series Alternator


Wiring Up a Ford G Series Alternator

Now that we figured out which one to use and went out and got one how can we wire it up?

Upgrade to a Ford 1G Alternator (100 Amp) and keep the external regulator

This alternator is a quick and dirty install/upgrade from a 55/65 amp. (Lester #7742) Sources for this one are 88-90 Ford Taurus; Lincoln Continental; Mercury Sable with 3.0 and 3.8 motors. This is an externally regulated unit so it is a good upgrade to keep your wiring intact.

Wiring up a Ford 2G Alternator eliminating the external regulator

This is the next level up and a very similar upgrade. Simple and effective solution with a one-wire hook-up.

Upgrade to a Ford 3G Alternator eliminating the external regulator and harness

The 3G alternator comes in outputs all the way to the 130 amp version. This is the one to get. Now it does come in a couple of flavors. Here are the details. The three choices are a 7 inch pivot mount, an 8.25 inch pivot mount and a side mount with horizontal bolts. The ones I will concentrate on here are the two pivot mount types because they closely resemble the factory style mount.

  • 65 Amp – Lester 7716
  • 75 Amp – Lester 7735
  • 130 Amp – Lester 7771

The D shaped regulator connector has 3 terminal lugs labeled I, A and S. The hookup is really simple.

  • I is the ignition on wire. This is a keyed hot wire.
  • A is the voltage sense wire. You loop this directly to the red B+ terminal on the back of the alternator.
  • S is the stator wire hooked to the stator connection which is the small spade connection right next to the large D-shaped connector.

The new charge wire goes from the red B+ lug to the battery. A 6 gauge or larger wire and a mega fuse in the 175/200 amp range complete the hookup. These can be salvaged from 90’s Ford Contour / Mystiques. The diagram shows the wire hookups and the most common Ford wire colors.

*** The wiring graphics are courtesy of RJM Injection Tech


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