Starter — general information and malfunctions (VW Sharan 1)

The main part of the starting system is a DC electric motor - a starter, powered by the battery. The starter consists of an electric motor, a drive mechanism and a traction relay. The starter is switched on by the contacts of its traction relay, which engages the starter pinion with the flywheel ring gear and also ensures the starter circuit is switched on when the switch contacts are closed. The drive mechanism transmits torque from the starter shaft to the flywheel through a gear transmission and, after the engine starts running, prevents the transmission of torque from the flywheel to the starter shaft. The starter is the most powerful consumer of electrical energy in a car.

Possible malfunctions, their causes and methods of elimination

Cause of malfunction	Method of elimination
When the ignition is turned on, the battery discharge indicator lamp does not light
1. The battery is discharged.	1. Start the engine using the auxiliary starting wires by "lighting up" or towing.
2. The control lamp has burned out.	2. Replace the burnt-out lamp.
3. The wires on the battery have become loose or the corresponding terminals have become oxidized.	3. Tighten the wire fastenings. Check the connections, if necessary, clean the terminals and battery terminals.
4. The electrical circuit between the ignition switch, the battery discharge indicator lamp and the generator is broken.	4. Contact the service station.
5. The fuse in the mounting block has blown.	5. Replace the fuse.
6. Carbon brushes or voltage regulator are faulty.	6. Replace the carbon brushes and voltage regulator.
The control lamp lights up when the engine is running
1. Slipping of the alternator drive belt	1. Adjust the belt tension.
2. Open or short circuit in the excitation winding power supply diodes.	2. Replace damaged diodes.
3. The voltage regulator is damaged.	3. Replace the voltage regulator.
4. Break in one or more generator valves.	4. Replace the rectifier unit.
5. Break or interturn short circuit in the stator winding, short circuit to ground.	5. Replace the generator stator.
6. Short circuit to ground of the generator excitation winding terminals.	6. Replace the generator rotor.
Increased generator noise
1. The generator pulley mounting nut is loose.	1. Tighten the nut.
2. The generator bearings are damaged.	2. Replace the bearings.
3. Interturn short circuit or short circuit to ground of the stator winding.	3. Replace the stator.
4. Short circuit in one of the generator valves.	4. Replace the rectifier unit.
5. Squeaking brushes.	5. Wipe the brushes and contact rings with a cotton napkin soaked in gasoline.

[The original text can be found on the portal: VWManual]