Bosch AL4121X Alternator

Bosch AL4121X Remanufactured Alternator

The Bosch AL4121X is a remanufactured 12-volt alternator built for charging-system performance in select Hyundai and Kia applications. It features an internal regulator, internal fan, clockwise rotation, and a 6-groove pulley to match the original belt drive setup.

Bosch Premium Alternators are remanufactured, tested, and built to deliver dependable electrical output for vehicles that need stable battery charging and consistent system voltage. This AL4121X alternator is a direct-fit replacement for select Hyundai Genesis, Hyundai Equus, and Kia K900 models.

Key Features

• Remanufactured Bosch alternator for 12-volt charging systems
• 180 amp amperage rating for strong electrical output
• Internal voltage regulator for integrated control
• Internal fan design for alternator cooling
• Clockwise rotation
• Includes pulley with 6-groove belt configuration
• Aluminum case and aluminum case material for OE-style construction
• Rear view main mounting ear clock position: 6 o’clock

Detailed Description

Bosch AL4121X is engineered as a remanufactured alternator for vehicles that require a 180 amp charging unit with a 6S-CP pulley type and 53.7 mm outside pulley diameter. The internal regulator and internal fan support stable operation in demanding electrical systems, while the aluminum housing helps maintain a factory-style fit and finish. This part number, AL4121X, is listed as an interchange for 373003F020.

Compatible With 2009-2016 Hyundai Genesis, 2011-2016 Hyundai Equus, and 2015-2017 Kia K900. The Bosch AL4121X is a practical replacement when the original alternator no longer maintains proper charging output or system voltage.

What This Alternator Helps Solve

• Battery warning light caused by low alternator output
• Weak charging performance during driving or idle
• Voltage instability affecting electrical accessories
• Starting issues related to insufficient battery recharge
• Charging-system failure from a worn or damaged alternator

Installation Notes and Tips

Verify pulley style, connector orientation, mounting ear position, and belt configuration before installation. This alternator is not one-wire capable and uses an internal regulator, so confirm the vehicle’s charging-system layout matches the listed specifications. For fitment-based searches, this part is commonly selected for a Hyundai Genesis alternator replacement, Hyundai Equus alternator replacement, or Kia K900 alternator replacement.

Quality Assurance

Bosch Premium Alternators are remanufactured, built, and tested to support reliable performance and consistent charging output. The AL4121X follows Bosch’s premium alternator standards for select Hyundai and Kia applications.