The VW Beetle uses an alternator to run electrical devices in your vehicle while the engine is running. A voltage regulator maintains a constant voltage level and is frequently integrated into the alternator assembly. If your battery continually runs down or your headlights become dimmer while the engine is running, you may need to replace the alternator.
Determine which alternator your VW Beetle will need. You'll want to be sure the new alternator is compatible with your Beetle's engine. The latest generation of the VW Beetle debuted in 1998 and comes in a variety of gasoline engines that include 1.4 L, 1.6 L, 1.8 L (normal and turbocharged), 2.0 L, 2.5 L and 3.2 L sizes. A 1.9 L diesel option is also available.
Disconnect the negative battery cable with a socket wrench. Remove the electrical wiring from the alternator. It may be helpful to label the wires as you do so.
Release the belt tension and remove the drive belt from the alternator pulley. Remove the mounting bolts with a socket wrench if you have a 2.5 L engine. Otherwise, remove the adjustment bolt followed by the pivot bolts for the alternator. This will allow you to carefully detach the alternator from its bracket.
Install the new alternator assembly on the bracket. Fasten the upper mounting bolt loosely if you have a 2.5 L engine. Otherwise, fasten the pivot bolt with a socket wrench and loosely install the adjustment bolt. Place the drive belt on its pulley and adjust the tension. Tighten all the bolts as required.
Connect the electrical wiring to the alternator and attach the negative battery cable with a socket wrench.
