Collection: 12SI Series Alternators, Parts, and Kits

10Si and 12Si Series Alternator for Tractor or Antique Vehicle Conversion

100% NEW, NO CORE CHARGE. Want HIGH AMP POWER from your Alternator but don't want to install an upgrade kit; we have the answer with our Complete 100% new Alternators. Each alternator is assembled with care using only Top Quality Brand New Components, except stator and rotor may be rewound, and upgraded to the higher amp specifications. Our Alternators are also covered by our 12 month unlimited mileage limited warranty. Sold outright, so you don't have to mess with a core or core charge. The alternators listed below are placed according to the years they were used with the most recent versions at the top of the page.

1983-1986 Delco Remy Type 12Si Series Internal Regulator, External Fan Alternator

The 12Si series alternator has the same outside dimensions as the 10Si series alternator (shown below) and will fit in it's place without modification. The 12Si series alternator has several design improvements over the 10Si series that make it the better choice between the two.

Improvements include:

Larger Rectifier to handle higher amperage
Wider Stator and Rotor:
- Improved Magnetism for better Low End Output
- Increased Mass for better Heat Dissipation
Larger Cooling Holes at back for better cooling of Rectifier, Stator and Other Internal Components
High Volume Axial Turbo Fan for Greater Air Flow through the alternator

Available in several amperage levels both standard hookup and self exciting (one wire) voltage regulators.

Unlike the competition, our Si series, self-exciting alternators include a special low-speed activation circuit. You don't need to rev the engine to get the alternator charging!

If You Want Superior Low End Output and Greater Reliability Check Out the 140,170 and 200 amp CS-144 Alternator... GM's #1 Factory Oversize High Output Alternator.