Keep your heavy-duty engine running reliably with this genuine Cummins alternator manufactured by Delco Remy. Engineered for durability and high performance, the 20SI series alternator delivers consistent 24V output and 50 amps of charging capacity — ideal for trucks, buses, construction, and industrial equipment powered by Cummins engines.

 

Fitting instructions can be found here: https://www.delcoremy.com/documents/alternator-instruction-sheets/installation-instructions-20si.aspx

 

Specifications

• Brand: Cummins / Delco Remy

• Model: 20SI

• Part Number (Cummins): 3930914

• Delco Remy P/N: 19010122

• Voltage: 24V

• Amperage: 50A

• Rotation: Clockwise / Bi-directional

• Mount Type: Pad Mount

• Pulley: Not included (shaft only)

• Origin: Assembled in Mexico

• OEM Quality: Genuine Cummins Engine Co. part

Compatible With

• Cummins industrial and truck engines (check with your specific model or serial number).

• Commonly found in medium to heavy-duty vehicles and stationary diesel applications.

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Features

• Heavy-duty internal regulator for consistent voltage control

• Rugged housing for maximum resistance to vibration and heat

• Genuine OEM part ensures perfect fit and long service life

• Backed by Cummins and Delco Remy quality standards

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Package Includes

• 1 × 20SI Alternator (24V / 50A)

• Protective packaging for safe transport

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Cross References

• Cummins: 3930914,

• Delco Remy: 19010122, 19010122A, 8600622

• Replacement for various OEM alternators used on Cummins-powered vehicles