Alternators is internally regulated, Will work as either a 1 or 3 wire operation, Includes a single groove pulley that will accept a V-style belt, Fits most 1965-\'85 GM\'s with straight mount 6.61 inch bolt spacing, Puts out 150 amp with 90 amps at idle, and 125 amps at cruising speed Powermaster 37293 GM 12SI 150 Amp Alternator, Chrome Sku # 25537293 Mfr. Part # 37293 Condition New Brand Powermaster Sold Each Details
Powermaster\'s most popular GM alternator fits most models, 1965-\'85 with straight mount 6.61 inch bolt spacing.
- Works as 1 or 3 wire operation
- Internally regulated
- Pulley included, single groove
- V-belt style
- 150 amp with 90 amps at idle, and 125 amps at cruising speed
Alternator FAQ (Link)
See the difference between the popluar alternators we offer by reading our tech article, GM Alternator Buying Guide (Link) and learn how to correctly install your new 1-wire alternator by reading our tech article, 1-Wire Alternator Conversion (Link).
Specs One Wire Alternator Yes Alternator Case Style GM 10SI/10DN/12SI Alternator Amperage 150 amp Voltage Required 12-Volt Regulator Internal Regulator Style Internal Alternator Finish Chrome Regulator Included Yes Alternator Pulley Included Yes Belt Width 0.375" Alternator Brackets Included No Overall Length 6.25" Color Chrome Sold in Quantity Each Centerline of Holes 6.61" MFG. Part # 37293 Notes Made in the USA GTIN Code 692209004387 Belt Included No Pulley Style V-belt Coating Type Plated Belt Type V-Belt Reviews Powermaster 150 amp alternator Rated by DtheM on June 19, 2026
Summary: Good quality nice looking alternator. Reads 14.9 output on ammeter with car running
Yes, I recommend this product.
Great replacement Rated by Hozona on September 24, 2025
Summary: With a chrome body, more amps this was a great repacement.
Yes, I recommend this product.
Would buy again Rated by None on September 10, 2025
Summary: Is working like it's supposed to
Yes, I recommend this product.
Excellent product, fixed my problem Rated by JAW II on September 03, 2025
Summary: This Powermaster 150amp alternator works great. It has taken my voltage from 11.1 volts with a/c on at an idle, to 13.2 volts. Very happy with this product.
Yes, I recommend this product.
Great product. Worked perfectly out of the box. Rated by PeteG on August 23, 2025
Summary: I install this item and checked its electrical ratings per the advertised specifications. It was spot-on! Great product and made the the great USA.
Yes, I recommend this product.
Related Items / Suggested Parts Speedway GM Internally-Regulated Alternator Wiring Harness Tech Support We\'re here to help before and after your purchase. If you have a question or need assistance with one of our products, please contact us through Messaging and a knowledgeable Speedway Motors team member will be happy to help. About Speedway Motors is America’s Oldest Speed Shop® and has been a trusted source for specialty rodding and racing products and friendly expert advice for more than 74 years. Founded in 1952 by “Speedy” Bill Smith – a racer and street rodder himself – Speedway has grown from a one-man operation to become the world’s largest manufacturer, distributor and retailer of street rod and racing products. Our industry-leading fast delivery is the result of same-day shipping from our state-of-the-art, centrally located 500,000 sq. ft. headquarters. Speedway’s size offers customers unmatched product selection and low pricing, while our excellent technical support and customer service have made us a recognized leader in the rodding and racing industries.
