If additional equipment is later installed on the vehicle, it is necessary to check whether the power of the installed alternator is sufficient. If necessary, a generator of higher power should be installed.
Since the battery can only be charged by the alternator, the alternating voltage of the alternator is converted to direct by the rectifier using a diode board. The voltage regulator changes the charging current by switching the excitation current on and off in accordance with 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. Damaged generator when buying a new or repaired generator is accepted by the manufacturer in offset. The old generator must be handed over.
Withdrawal
1. Disconnect the negative cable (-) battery with the ignition off. The battery is located in the luggage compartment behind the cover on the right side. For BMW 316i, 318i, the battery is located in the engine compartment.
Disconnecting the battery clears the fault memory of some controls. If necessary, read the fault memory before disconnecting the battery. Refer to Section Troubleshooting. It is desirable to carry out work in the conditions of a service station.
2. Cover the negative battery terminal to prevent accidental contact.
3. Models 316i, 318i, 320i, 323i, 328i: remove the intake air filter box, refer to Section Removal and installation of the engine air filter.
4. Models 320i, 323i, 328i with air conditioning: Disconnect the fan with a viscous coupling from the coolant pump, refer to Section Removing and installing a viscous fan.
5. Models 320d: Remove the radiator shutters, refer to Section Removal and installation of a 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 of the hydraulic booster pump.
7. Remove the V-belt, refer to Section Removing, installing and tensioning the V-belt.
8. Disconnect and remove the top deflection roller.
9. Disconnect the ventilation hose behind the generator, if present.
10. Unscrew the protective cap from the back of the generator. If there are connection nut covers, remove them.
11 Remove the cover. Unscrew the nuts -1- and remove the thick connecting cable B+ and thin D+. On the 320i, 323i, 328i engine, disconnect the D+ terminal connector on the back of the alternator while pushing in the wire retainer.
12. Turn away a bolt -2 - accession of a negative cable.
13. Turn away bolts of fastening (arrows in the illustration) and remove the generator.
Installation
14. Models 316i, 318i: For simplification of installation of the generator press plugs -1- on a beam of the engine in position -2-.
15. Secure the generator by tightening the mounting bolts to a torque of 45 Nm.
Note for 316i, 318i: 1 - thread for deflecting roller with hydraulic V-belt tensioner. If installed - thread -1- is not used.
16. Attach the top deflector roller.
On 320i, 323i, 328i engine, the anti-twist on the deflector roller holder must engage in the groove (arrow illustration) on the generator.
17. Fix the cable on the back of the generator and dock it, refer to subsection "Withdrawal". M6 nuts are tightened with a torque of 7 Nm, M8 nuts with a torque of 13 Nm.
18. Attach the cover to the back of the generator.
19. Models 320d: Attach the power steering pump pulley. After installing the V-belt, fix the pulley, refer to Section Removal and installation of the hydraulic booster pump.
20. Install the V-belt, refer to Section Removing, installing and tensioning the V-belt.
21. Models 320d: Install the radiator shutters, refer to Section Removal and installation of the fan/fan shroud.
22. Models 320i, 323i, 328i with air conditioning: fix the fan with a viscous coupling to the coolant pump, refer to Section Removing and installing a viscous fan.
23. Models 316i, 318i, 320i, 323i, 328i: Install the suction air filter box, refer to Section Removal and installation of the engine air filter.
24. Connect the negative cable (-) battery with the ignition off. Set the clock.