Check for a broken accessory drive belt. If the belt is intact, check its tension
Press the top of the belt with your thumb and see how much it flexes
If the deflection is not correct, adjust the tension or replace the belt.
If the belt is properly tensioned, check for a blown 90 A fuse in the fuse box located in the engine compartment next to the battery.
This fusible link (shown by the arrow in the photo, the fuse block cover is removed) protects, among other circuits, the generator circuit.
If the fusible link is blown, replace it and start the engine.
If the voltage reading on the display is no longer blinking (the voltmeter needle is in the green zone of the scale, the battery discharge warning light has gone out), then the voltage is normal and you can continue driving.
Possible generator malfunctions and solutions
When the engine is running at medium speed, the voltage indicator shows below 12 V:
- Faulty voltage regulator
Replace voltage regulator
- The drive belt is loose
Tighten the belt
- Broken wires from <+> or <W>
- Missing or unreliable contact between brushes and slip rings
Clean the brush holder from dirt, check the force of the brush springs, clean or grind slip rings
- Open excitation circuit
Repair the open circuit, especially carefully check the soldering points of the excitation coil leads to the slip rings and the serviceability of the coil leads
- Interturn short circuit or open circuit in one of the phases of the stator winding of the generator
Disassemble the generator, check the stator winding for open and short circuits
Replace a stator with a defective winding
- Failure of one of the diodes of the rectifier unit
Check the diodes with instruments or a test lamp
Replace the block with faulty diodes
Quick wear of brushes and slip rings:
- Increased slip ring runout
Turn and grind slip rings
- Oil getting on slip rings
Wipe slip rings and brushes with a cloth soaked in gasoline
- Increased or reduced brush spring pressure
Check brush spring pressure
Increased generator noise:
- Insufficient amount of grease in the bearings
- Rotor touching the starter poles
Replace generator cover
- Bearing wear
- Bearing seizing
- Development of a bearing seat
Replace generator cover
- The tightening screws of the generator covers have loosened
Tighten the clamping screws with a torque of 0.5 kgf.m
Breakage of the bracket and paws for fastening the generator. Frequent loosening of the generator:
- Incorrect installation of the generator on the brackets
- Increased pulley or rotor imbalance
Check dynamic balance of pulley and rotor.
If the unbalance exceeds 10 gsm, balance the parts
- Increased motor imbalance
Check engine dynamic balancing