VOLTAGE REGULATORS
The voltage regulator turns the alternator or generator on and off and makes it charge the battery. If the battery is boiling, it is being overcharged and the voltage regulator is definitely bad. If the battery is being undercharged, it's not so easy, it could be the voltage regulator, a loose alternator belt, bad battery or a bad alternator. Further analysis is required.
VW alternators 1980-1997 have an easy to change voltage regulator. In most cases it is just two screws. It can be done without removing the alternator.
Before buying a new Alternator check the brush length on the voltage regulator or brush holder. Many times new brushes are the solution. New they have approx. 3/8" useable brush length. Brushes come with (C) but not alternators used on Rabbit, Scirocco ‘73-84.
Voltage Regulator
All Rabbits, Jettas, Sciroccos, Dashers ‘75-84 use either A or C.
(A) is Motorola Type (w/o brushes)
#3023 . . . . .$39.95
(B) Most Bugs
#3024 12 Volt ‘67-73 . . . . .$37.95
#5854 6 Volt ‘61-66 . . . . . .$44.95
#3022 12 Volt external motorola fits under back seat some ‘73-74 . . . .$69.95
#3020 Not shown 12 Volt external Bosch fits under back seat some ‘72-74 . .$89.95
#11885 Not shown 12 Volt Internal regulator most ‘75-79 . . . . . .$49.95
MOST COMMON
(C) Bosch Type Rabbit, Jetta
‘77-84 and all Golf, Jetta,
Vanagon, Sciroccos,
Quantum, Passat ‘85-92 and
some to ‘95
#10138 . . . . .$39.95
(D) Bus ‘72-79 Not shown
#3020 . . . . . .$89.95
