Alternator, 55 Amp, for Aircooled VW

Product Overview

Upgrade your vintage Volkswagen''s electrical system with the industry-standard EMPI 55 Amp Alternator, the definitive solution for owners looking to move beyond the limitations of the antiquated 12-volt generator. Whether you are building a high-performance street machine, a rugged off-road dune buggy, or restoring a classic Beetle to its former glory, modern electrical demands require more than what the original factory equipment can provide. This EMPI alternator delivers a consistent 55 amps of charging power, ensuring that your ignition system, high-output headlights, and modern stereo equipment all receive the stable voltage they need to operate at peak efficiency. By eliminating the common "dimming lights at idle" syndrome associated with old generators, this unit provides the reliability and peace of mind necessary for long-distance cruising and daily driving alike.

Engineered for a seamless transition, this 55 Amp Alternator features a built-in internal regulator, which simplifies your engine bay by allowing you to bypass and remove the bulky external regulator used in older charging systems. The cast aluminum housing is designed to withstand the high-heat environment of the air-cooled engine compartment, while the precision-balanced internals ensure smooth operation even at higher RPMs. When you choose this EMPI component from Appletree Automotive, you are investing in a part that has been the "go-to" upgrade for VW enthusiasts for decades. It is not just about charging the battery; it''s about modernizing the heart of your VW''s electrical grid to handle the rigors of today''s driving conditions without sacrificing the iconic look of your flat-four engine.

Vehicle Fitment

This alternator is designed for Type 1 based air-cooled engines. Note that when converting from a generator, an alternator-specific stand and backing plate are required.

• Volkswagen Beetle: 1967-1977 (Standard and Super Beetle)
• Volkswagen Karmann Ghia: 1967-1974
• Volkswagen Type 2 Bus: 1967-1971 (1600cc engines)
• Volkswagen Thing: 1973-1974
• Dune Buggies & Sand Rails: All models utilizing a VW Type 1 upright engine configuration.
• Retrofit Applications: Can be used on 1954-1966 models that have been converted to a 12-volt electrical system.

Technical Specifications

• Output Rating: 55 Amps
• Voltage: 12 Volts
• Regulator Type: Internal (Built-in)
• Housing Material: High-Strength Cast Aluminum
• Finish: Natural Machined Aluminum
• Part Number: 00-9445-7
• GTIN: 707924339659
• Shipping Weight: 11.3 lbs
• Pulley Shaft Diameter: Standard VW Alternator Taper

Pro Tips from the Master Tech

Tip 1: Navigating the External Regulator Bypass

When upgrading from a stock generator to this internally regulated alternator, you must bypass your existing external voltage regulator. Many novices simply plug the wires in, but for the system to charge correctly, you need to join the heavy-gauge B+ wires together and connect the small wire (usually blue) from the charging light on your dash directly to the D+ terminal on the new alternator. Failing to do this correctly will result in a battery that won''t charge and a warning light that stays on. Always double-check your wiring schematic before the first startup to prevent "frying" the internal diodes.

Tip 2: Proper Stand and Backing Plate Alignment

You cannot bolt an alternator directly onto a generator stand. To ensure a professional installation, you must use an alternator-specific engine stand (pedestal) and a 3-piece alternator backing plate kit. Because the alternator housing is physically larger than a generator, the backing plate and the cooling fan must be perfectly centered. Before tightening the large 36mm fan nut, spin the assembly by hand to ensure there is no rubbing against the fan shroud. A tiny misalignment here can lead to annoying metallic screeching or even catastrophic failure of the cooling fan at high speeds.

Tip 3: Belt Tension and Pulley Shimming

Belt tension is critical on air-cooled Volkswagens because the fan belt doesn''t just drive the alternatorit drives the entire cooling system. When installing this EMPI unit, use the proper number of shims between the pulley halves to achieve approximately 1/2 inch of deflection in the belt. If the belt is too tight, it will put excessive side-load on the alternator bearings, leading to premature failure. If it is too loose, it will slip, causing the engine to overheat and the charging system to underperform. Check your belt tension again after the first 50 miles of driving, as new belts tend to stretch slightly during their initial break-in period.