V900156 Dual Alternator Incompatibility

Technical Support Subject V900156 Dual Alternator Incompatibility Version Document Department Revision Details Author Reviewed by Implemented Tech. Eng. A EXT-UH-020 Tech Document Release BDJ JWL KRM 13 Jan 2026 Page 1 of 1 Knowledge Base: http://kb.vmacair.com/ Email: tech@vmacair.com Web: www.vmacair.com Technical Support: 1(888)241-2289 Sales:1(800)738-8622 Fax: 1(877)740-3201 SYSTEM OR PARTS AFFECTED V900156 UNDERHOOD®70 Air Compressor System for 2025+ Dodge / RAM · 2500 Pick Up, 3500 Chassis Cab, 3500 (Pickup), 4500 (Chassis Cab), 5500 (Chassis Cab). OVERVIEW Installing the V900156 system in a vehicle originally equipped with dual alternators is considered “out of application” and will void the VMAC warranty. • The V900156 UNDERHOOD 70 air compressor system is not compatible with vehicles equipped with dual alternators. • While the removal of the secondary alternator is physically possible, doing so will negatively impact charging system performance and will cause the vehicle to display error codes. • RAM dealers are unlikely to reprogram the vehicle to disable the secondary alternator.