Removal and installation the generator (BMW 3 Series E46)

The car has an alternator. The generator is driven by the crankshaft via a V-belt. Depending on the car model and equipment, generators of different power can be installed. The power is indicated on the plate attached to the generator.

If additional equipment is installed on the vehicle at a later date, it is necessary to check whether the installed generator has sufficient power. If necessary, a generator with higher power should be installed.

Since the battery can only be charged by the generator, the alternating voltage of the generator is converted into direct voltage by the rectifier using the diode board. The voltage regulator changes the charging current by switching the excitation current on and off according to the state of charge of the battery. At the same time, the regulator maintains a constant operating voltage of about 14 V, regardless of the speed.

The generator is a replaceable part. A damaged generator is accepted by the manufacturer as a trade-in when purchasing a new or repaired generator. The old generator must be handed in.

Removal

1. Disconnect the negative (-) battery cable with the ignition off. The battery is located in the luggage compartment behind the cover on the right side. In BMW 316i, 318i cars, the battery is located in the engine compartment.

Disconnecting the battery will erase the fault memory of some control units. If necessary, read the fault memory before disconnecting the battery. Refer to Section Troubleshooting. It is advisable to carry out the work in a service station.

2. Cover the negative battery terminal to prevent accidental contact.

3. Models 316i, 318i, 320i, 323i, 328i: remove the air filter box on the intake, refer to Section Removal and installation the engine air filter.

4. Models 320i, 323i, 328i with air conditioning: Disconnect the viscous fan from the coolant pump, refer to Section Removal and installation a fan with a viscous coupling.

5. Models 320d: Remove the radiator shutters, refer to Section Removal and installation the radiator.

6. Models 320d: Before removing the V-belt, loosen the three mounting bolts on the power steering pump pulley without unscrewing them. After removing the V-belt, disconnect the pulley. Power steering pump refer to Section Removal and installation the power steering pump.

7. Remove the V-belt, refer to Section Removal, installation and tensioning the V-belt.



8. Disconnect and remove the upper deflection roller.

9. Disconnect the ventilation hose from behind the generator, if equipped.



10. Unscrew the protective cap from the back of the generator. If there are covers for the connection nuts, remove them.



11 Remove the cover. Unscrew the nuts "1" and remove the thick B+ and thin D+ connection cables. For the 320i, 323i, 328i engine, disconnect the D+ terminal connector from the back of the generator by pressing in the wire retainer.

12. Unscrew bolt "2" connecting the negative cable.



13. Loosen the mounting bolts (arrows in the illustration) and remove the generator.

Installation

14. Models 316i, 318i: To facilitate installation of the generator, press the bushings "1" on the engine beam to position "2".



15. Secure the generator by tightening the mounting bolts to a torque of 45 Nm.



Note for 316i, 318i: 1 – thread for the deflection roller with a hydraulic V-belt tensioner. If installed, thread "1" is not used.



16. Secure the upper deflection roller.

For the 320i, 323i, 328i engine, the anti-rotation stop on the deflection roller holder must fit into the groove (arrow on the illustration) on the generator.

17. Secure the cable to the back of the generator and connect it, refer to the "Removal" subsection. The M6 nuts are tightened to 7 N·m, the M8 nuts to 13 N·m.

18. Secure the cover to the back of the generator.

19. Models 320d: Secure the power steering pump pulley. After installing the V-belt, secure the pulley, refer to Section Removal and installation the power steering pump.

20. Install the V-belt, refer to Section Removal, installation and tensioning the V-belt.

21. Models 320d: Install the radiator shutters, refer to Section Removal and installation the fan/fan shroud.

22. Models 320i, 323i, 328i with air conditioning: secure the viscous coupling fan to the coolant pump, refer to Section Removal and installation a fan with a viscous coupling.

23. Models 316i, 318i, 320i, 323i, 328i: Install the air intake filter box, refer to Section Removal and installation the engine air filter.



24. Connect the negative (-) battery cable with the ignition off. Set the clock.