400 Amp RVC Bypass Alternator - 2007-2013 6.6L Duramax LMM/LML & 2005-2013 GM Gas - Purple Billet

400 Amp High Output Alternator for 2007-2013 6.6L Duramax LMM/LML

Fits the 6.6L Duramax in 2007-2013 Chevrolet and GMC HD trucks (LMM and early LML) and the 2005-2013 GM gas trucks that share the same case and mount. This is a direct bolt-in upgrade over the factory unit — same mount, same pulley position, no bracket modification.

Diesel engines spend most of their working life at low RPM, and that is exactly where a stock alternator runs out of headroom. This unit holds 200+ amps at engine idle and delivers a full 400+ amps at cruising speed, hot rated — enough for a lift pump, auxiliary lighting, a winch, a plow, a welder or a competition-grade stereo without watching your voltage sag at every stoplight.

Engine codes covered: LMM, LML

Vehicles: Silverado Sierra 2500HD 3500HD, Suburban, Tahoe, Escalade, Avalanche

Manufacturer specifications and full fitment

Installation Notes:

This unit comes equipped with a smaller 1.75 inch diameter alternator pulley, and will require a slightly shorter drive belt for proper belt tension.  Not recommended for sustained use above 5,000 RPM engine speed. ((Check instructions section for finding belt sizes and wiring)). If you DO NOT use the correct shorter belt, this will result in very low to no output and create extra work load for the alternator.

Newly redesigned for 2020, The Elite series offers the highest possible amperage and durability available in a large case alternator. 6 phase technology combined with massive twin rectifier assemblies and 12 diodes makes these alternators totally durable for daily use, while still maintaining 200+ amps at engine idle speeds.

These alternators use the more robust 4 pin style regulator than the OE 2 pin ECU controlled alternator. There is no extreme voltage fluctuation as this will bypass the RVC charging system on all 2005> GM truck applications. Simply install the included 1 wire P101 harness to a tested 12v switched source and plug in the included P103 module into the vehicles 2 pin original alternator wiring harness. No check battery light, no computer controlled voltage swings. The voltage you want, when you want it!

Fitments: