621-120-J10 - Balmar 120 AMP 12V Alternator with Isolated Ground | Aztek Computers
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SKU: YZ0O4XXLWY |  Mfg. Part: 621-120-J10  | UPC: 676205751186  |  0 Reviews  |     Share Make an offer

621-120-J10 - Balmar 120 AMP 12V Alternator with Isolated Ground & J10 Pulley

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$731.74  $987.85
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Product Overview

120 AMP 12V Alternator with Isolated Ground & J10 Pulley

This high-performance alternator is designed for use in various marine applications. Featuring a robust 120A output at 12V, it utilizes a spindle mount with a single foot design and includes a J10 AltMount serpentine pulley. The alternator is equipped with an isolated ground to ensure optimal performance in demanding conditions.

Compatible with multiple engine brands, this alternator is a reliable choice for automotive and marine professionals alike. It fits engines from Westerbeke, Lehman, Hino & Pathfinder, as well as Volvo Penta (Gas & Diesel), John Deere, Perkins, Mercruiser, Pleasurecraft, Crusader, Indmar, Marine Power, and other GM-based engines.

Replacement Part: 621-120-SR-IG

Note: This product may not be returned to the original point of purchase. For any issues or concerns, please contact the manufacturer directly.

Expert Overview

The Balmar 621-120-J10 is a 120 Amp, 12-Volt alternator designed for marine and automotive applications requiring a robust power source. This unit features an isolated ground configuration, which is beneficial for maintaining system integrity in challenging electrical environments. It utilizes a spindle mount with a single foot design and comes equipped with a J10 AltMount serpentine pulley, facilitating installation in compatible systems. This alternator is suitable for IT professionals and maintenance teams managing power systems in marine vessels or industrial equipment that rely on specific engine types. It addresses the need for a reliable 12V charging solution for engines from manufacturers such as Westerbeke, Lehman, Hino, Pathfinder, Volvo Penta (Gas & Diesel), John Deere, Perkins, Mercruiser, Pleasurecraft, Crusader, Indmar, Marine Power, and other GM-based engines. Its 120A output ensures sufficient power generation for onboard electrical demands.

Technical Specifications

  • Output: 120 Amp at 12 Volts
  • Spindle Mount (Single Foot) Design
  • Includes J10 AltMount Serpentine Pulley
  • Isolated Ground Configuration
  • Compatible with a variety of marine engine brands
  • Replacement for part number 621-120-SR-IG

Product Details

  • Manufacturer:
  • Model Number:
  • UPC:
  • Condition:
  • Weight:
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  • Updated:
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  • Country of Origin:
  • Balmar
  • 621-120-J10
  • 676205751186
  • New
  • 6.9 lbs
  • 10 X 8 X 10
  • Aug 14, 2026
  • May 01, 2026
  • United States
Product Identifiers: Brand: Balmar • Part #: 621-120-J10 • UPC: 676205751186 • Category: 12-Volt Portable Appliances

Frequently Asked Questions

What engine brands is this alternator compatible with?

This alternator is compatible with engines from Westerbeke, Lehman, Hino, Pathfinder, Volvo Penta (Gas & Diesel), John Deere, Perkins, Mercruiser, Pleasurecraft, Crusader, Indmar, Marine Power, and other GM-based engines.

What type of pulley is included with this alternator?

The alternator includes a J10 AltMount serpentine pulley.

What is the benefit of an isolated ground configuration?

An isolated ground configuration helps ensure optimal performance, particularly in demanding conditions, by separating the alternator's ground from the engine block or chassis ground.

What are the key output specifications of this alternator?

This alternator provides an output of 120 Amps at 12 Volts.

621-120-J10 - Balmar 120 AMP 12V Alternator with Isolated Ground & J10 Pulley

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