Possible generator malfunctions, their causes and methods of elimination (VAZ-21011)

Cause	Method of elimination
The indicator light is on or comes on intermittently while the car is moving
Alternator drive belt slippage	Adjust the belt tension
Open circuit in connection between plug "85" of charge indicator lamp relay and generator star center	Check and restore the connection
The charge indicator lamp relay is misadjusted or damaged	Check the relay, adjust it or replace it
Open circuit in the excitation winding power supply circuit	Restore connection
The voltage regulator is out of adjustment or damaged	Clean the contacts, adjust or replace the regulator
Worn or stuck generator brushes; oxidation of slip rings	Replace the brush holder with brushes; wipe the rings with a rag soaked in gasoline
Open or short circuit to ground of the generator excitation winding terminals	Connect the winding leads to the slip rings or replace the rotor
Short circuit of one or more "positive" generator valves	Replace the generator rectifier block
Break in one or more generator valves	Replace the generator rectifier block
Open circuit in the connection between plugs "86" and "87" of the charge indicator lamp relay	Restore connection
Open circuit or interturn short circuit in the stator winding	Replace generator stator
The indicator lamp does not light when the ignition is turned on
The filament burned out	Replace the lamp
The charge indicator lamp relay is misadjusted or damaged	Clean the contacts, adjust or replace the relay
Open circuit in connection between plug "87" of charge indicator lamp relay and plug "I" of fuse box	Restore connection
Short circuit of one or more "negative" generator valves	Replace the generator rectifier block
Short circuit of stator winding to ground	Replace the stator
The generator is working, the battery is charging weakly
Weak belt tension; slippage at high speed and when the generator is running under load	Adjust the belt tension
The fastening of the wire ends on the generator and battery is loose; the battery terminals are oxidized; the wires are damaged	Clean the battery terminals from oxidation, tighten the clamps, replace damaged wires
The battery is faulty	Replace the battery
The voltage regulator is out of adjustment or damaged	Clean the contacts, adjust or replace the voltage regulator
The battery is recharging
Poor contact between ground and the voltage regulator housing	Restore contact
The voltage regulator is out of adjustment or damaged	Adjust or replace the voltage regulator
The battery is faulty	Replace the battery
Increased generator noise
The generator pulley nut is loose	Tighten the nut
Fan blades are bent	Straighten the fan or replace it
The generator bearings are damaged	Replace the bearings
Interturn short circuit or short circuit to ground of the stator winding (generator howl)	Replace the stator
Short circuit in one of the generator valves	Replace the rectifier unit
The creak of brushes	Wipe the brushes and contact rings with a cotton cloth soaked in gasoline