Generator — Checking, Removing and Installing (Opel Vectra C)

General information

1. The vehicles in question use an alternator. When installing additional electrical equipment, check that the generator capacity is sufficient to supply new consumers with electricity.

2. The generator is driven by a multi-ribbed belt from the engine crankshaft.

3. The generator is an electric machine with electromagnetic excitation. To convert alternating current into direct current, a rectifier is built into the generator. Output voltage is adjusted by a built-in regulator.

4. When the generator is operating, the electric current flowing through the excitation winding creates a magnetic flux around the rotor poles. When the rotor rotates, its magnetic poles periodically change under each stator tooth, as a result of which the magnetic flux passing through the teeth continuously changes in magnitude and voltage. This variable magnetic flux creates an electromotive force (EMF) in the stator winding.

5. At high rotor speed, when the generator output voltage begins to exceed 13.6-14.5 V, the voltage regulator is locked, and the current does not pass through the excitation winding. When the voltage decreases, the regulator is unlocked again, providing freedom of current flow through the excitation winding. The higher the rotor speed, the longer the regulator remains locked and, accordingly, the more the voltage at the generator output decreases. The process of locking and unlocking the regulator occurs at a high frequency, so the output oscillations remain almost unnoticeable and the generator voltage can be considered constant, maintained at a level of 13.6-14.5 V.



6. The charging system does not require periodic maintenance, however, the condition of the alternator drive belt, battery and its wiring should be checked and replaced on a regular basis in accordance with the maintenance schedule (see Chapter 1).

7. The serviceability of the charging system is monitored using the corresponding lamp on the instrument cluster.

Safety precautions when servicing a generator

• Do not disconnect the battery or voltage regulator while the engine is running;
• Do not short the generator excitation terminal or the cable attached to it to ground;
• Do not confuse the order of connecting the voltage regulator wiring;
• When charging the battery without removing it from the vehicle, make sure that both cables are disconnected from it;
• Remember that turning on a voltage regulator shorted to ground will cause it to fail immediately;
• Never remove the alternator while the battery is connected;
• Never use voltage meters or test lamps connected to household power (110/220 V) when testing on-board electrical equipment;
• When checking the condition of the diodes, do not apply a voltage higher than 12 V to them and do not use meggers that also have a high output voltage - a breakdown of the diodes will lead to a short circuit. Remember that when checking the insulation of the wiring with a megger, it is necessary to disconnect all the wiring from the generator;
• Before carrying out any electric welding work on the vehicle, do not forget to disconnect the electrical wiring from the generator and battery;
• Any checks of the circuits and components of the on-board electrical wiring should be carried out with the engine not running and the battery disconnected;
• Remember that reversing the polarity of any connections carries the risk of irreversible failure of the rectifier and generator voltage regulator.

Checking the generator voltage

8. If the battery does not charge or is not charged sufficiently while the vehicle is moving, the generator voltage must be checked.

9. Connect a voltmeter between the positive and negative terminals of the battery and start the engine. The voltage at start-up should drop to approximately 8 V (at an ambient temperature of +20°C)

10. Increase the engine speed to 3000 rpm - if the generator and regulator are working properly, the voltage at the terminals should be from 13 to 14.5 V

11. To check the voltage stability, turn on the high beam and repeat the measurements at 3000/min. The measured voltage should increase by more than 0.4 V from the previously measured values.

12. If the readings go beyond the nominal value, the generator and regulator must be checked in a specialized workshop.

Removal and installation

Engine Z16XE/Z18XE

13. Disconnect the cable from the negative terminal of the battery. (see Section 8), remove the multi-rib belt and belt tensioner (see Chapter 2).

14. Disconnect the electrical wiring connector (see accompanying illustration) engine oil pressure sensor, loosen the mounting nut, unscrew the 2 upper generator bracket mounting bolts and loosen the lower bolt.





15. Lower the car onto its wheels and remove the engine cover.

16. Remove the EVAP valve.

17. Loosen the 2 mounting nuts (see accompanying illustration) and disconnect the supply wiring from the generator.



18. On models equipped with the Z16XE engine, unscrew the 2 upper mounting bolts, and on models with the Z18XE engine - 1 upper and 1 lower mounting bolt, remove the generator together with the mounting bracket and remove them from the engine compartment. If necessary, unscrew the bolts and remove the bracket from the generator.

19. Installation is performed in the reverse order of removal. In this case, the bushing of the multi-rib belt tensioner must coincide with the hole in the generator support.

Engines Z22SE/Z22YH

20. Disconnect the cable from the negative terminal of the battery.

21. Remove the multi-rib belt.

Note: The belt is removed from below.

22. Loosen the nut and remove the front engine mount axle bolt.

23. Lower the car onto its wheels, add coolant and remove the engine cover.

24. Remove the air cleaner and disconnect the upper coolant hose from the cylinder head.



25. Remove the EVAP valve (see Chapter 4).

26. Remove the right engine mount using a lifting device and raise the engine approximately 3.5 cm.

27. Disconnect the connector (see accompanying illustration) and loosen the generator wiring nut. Unscrew the 4 mounting bolts, remove and take out the generator from the engine compartment.



28. Installation is carried out in reverse order.

Z32SE Engine

29. Disconnect the cable from the negative terminal of the battery.

30. Remove the multi-rib belt.

31. Remove the intermediate drive shaft and disconnect the right stabilizer bar from the shock absorber.

32. Unbolt the starter screen, loosen the 2 nuts securing the generator wiring and disconnect the wires.

33. Remove 2 bolts and remove the generator from the engine compartment from below.

34. Installation is carried out in reverse order.

Engine Z19DT(H)

35. Disconnect the cable from the negative battery terminal (see Chapter 5) and remove the engine cover (see Chapter 2).

36. Remove the fuel filter housing from the mounting clamp and remove the latter (see Chapter 4, Section 10).

Note: For ease of work, the fuel filter can be removed completely.

37. Raise the vehicle on a lift and remove the multi-rib belt (see Chapter 2).

38. Remove the bolt (see accompanying illustration) generator mounts and lower the vehicle.



39. On the Z19DTH engine, remove the 2 bolts securing the upper holder of the generator wiring harness and separate the harness.

40. Loosen the 2 nuts and disconnect the generator wiring.

41. Turn inside out 2 (on the Z19DT engine one) upper mounting bolts, remove and lift the generator out of the engine compartment.



42. Installation is carried out in reverse order.

Engines Y20DTH/Y22DTR

43. Disconnect the cable from the negative terminal of the battery (see Section 8), and remove the multi-rib belt (see Chapter 2).

44. Remove the exhaust system (see Chapter 4).

45. Remove 2 bolts, loosen 1 nut and remove the starter screen.

46. Disconnect the connector (see accompanying illustration) engine oil pressure sensor wiring, loosen the two nuts and disconnect the generator wiring, unscrew the mounting bolt and separate the cable channel housing.



47. Lower the car onto its wheels and remove the engine cover.

48. Remove the 2 upper bolts securing the generator cable channel casing.

49. Remove the air intake tract.

50. Release the hose (see accompanying illustration) cooling system from the upper holder, loosen the generator mounting nut and remove the hose holder.





51. Raise the vehicle on a lift, unscrew the 3 mounting bolts and remove the steering heat shield.

52. Loosen the lower nut (see illustration 10.50) generator mounts. Remove the upper and lower mounting bolts and lift the generator downwards out of the engine compartment, while holding the cable channel cover.

53. Installation is carried out in reverse order.

Y30DT Engine

54. Remove the engine oil dipstick and close the tube with a suitable plug.

55. Remove 4 screws and remove the engine cover.

56. Remove the battery with the mounting tray.

57. Loosen the mounting clamp, disconnect the lower connecting piece from the turbocharger and move it aside.

58. Remove the expansion tank, loosen the nut and release the expansion tank hose from the holder. Unbolt the holder.

59. Separate the wiring harness from the transmission and move it to the side. Disconnect the turbocharger heat shield.

60. Remove the multi-rib belt and belt tensioner (see Chapter 2) and the exhaust system (see Chapter 4).

61. Remove the 2 bolts, 2 nuts and catalytic converter support bracket, then remove the 2 nuts and catalytic converter heat shield.

62. Remove the multi-rib belt guide roller (see Chapter 2).

63. Remove the right drive shaft (see Chapter 8).

64. Loosen the 2 nuts and disconnect the electrical wiring from the generator. Release the electrical wiring from the holder, unscrew the bolt and remove the holder.

65. Disconnect the generator cable channel housing and starter wiring and move them to the side.

66. Unscrew the 2 generator mounting bolts, turn it with the pulley towards the steering gear housing and remove the generator from the engine compartment.

67. Installation is performed in the reverse order of removal. After installation, check the coolant level and make the appropriate adjustments if necessary.