Volkswagen: battery light is on, sense wire, batery

Question
i have vw beetle 2002 , the batery light is on , i changed the battery , and still on , is the alternator is bad or , there is some fuse to check befor i change the alternator ?

Answer
Richard,
 Try this:  Disconnect the smaller alternator sense wire at the back of the alternator.  If the dash board light does not go out, there is a short in this wire circuit or the instrument cluster is bad; there is nothing wrong with the alternator or battery.  If the light goes out, then you need to test the voltage at the battery.  If the battery is fully charged it should measure just over 12 volts with the engine off.  Now turn the engine on.  The voltage should be just over 14 volts.  If the voltage is too low, the alternator is bad.  If too high, the regulator is bad.  The regulator can be replaced independent of the alternator; it is mounted on the back of the alternator.

- Rick