How to Replace the Alternator in a VW Passat

The alternator in a VW Passat operates various accessories in the vehicle by transmitting an electrical current while the engine is running. The alternator assembly frequently includes a voltage regulator that maintains a constant voltage level. If your headlights become dimmer while driving or your battery keeps running down, you may need to replace the alternator.

Instructions

1

Determine which alternator your VW Passat needs. Be sure the new alternator is compatible with your Passat's engine. Models made before 1982 are equipped with a 1.3 L, 1.4 L, 1.6 L or 1.5 L diesel engine.

2

Look at later models of the VW Passat. Models built from 1982 to 1987 may have a 1.3 L, 1.5 L, 1.6 L, 1.8 L, 1.9 L, 2.0 L and 2.2 L gasoline engines in addition to 1.5 L, 1.6 L and 1.8 L diesel engines. Engine choices for 1988 to 1993 models include 1.6 L, 1.8 L, 1.9 L, 2.0 L and 2.8 L sizes.

3

Examine engines for recent models of the VW Passat. Models made from 1994 to 1997 have 1.6 L, 1.8 L, 2.0 L, 2.8 L and 2.9 L gasoline engines and a 1.9 L diesel engine. Models built from 1996 to 2000 also offer a 2.3 L gasoline engine and 2.5 L diesel engine. The 2.9 L engine was replaced with a 4.0 L engine for 2001 to 2004 models.

4

Look at the engines for the VW Passat made after 2005. These models may have a 1.4 L, 1.6 L, 1.8 L, 2.0 L, 3.2 L and 3.6 L engine. This model is also available with a 1.9 L and 2.0 L diesel engine.

5

Disconnect the negative battery cable with a socket wrench. Label the wires, if necessary, and remove the electrical wiring from the alternator.

6

Release the belt tension so you can remove the drive belt from the alternator. Remove the mounting bolts with a socket wrench if you have a 2.5 L engine. Otherwise, use a socket wrench to remove the adjustment bolt and then the pivot bolts for the alternator. This allows you to carefully detach the alternator from its bracket.

7

Install the new alternator assembly on the bracket. Install the upper mounting bolt on 2.5 L engines with a socket wrench. Otherwise, fasten the pivot bolt and loosely install the adjustment bolt. Place the drive belt on its pulley and adjust the tension. Tighten all the bolts as required.

8

Connect the electrical wiring as indicated by your labels and connect the negative battery cable with a socket wrench.