90 A (Bosch) With V-Belt

Generator (GEN), repairing - 90 A (Bosch) with V-belt







1 - Hex nut
- 50 Nm (37 ft lb)
2 - Washer
3 - Pulley
- Diameter 74 mm (2.9 in.)
- Removing/installing ~ Fig. .4
4 - Spacer sleeve
5 - Washer
6 - Fan
- Note direction of rotation, marked with arrow
7 - Bolt
- M4 x 20
8 - Bolt
- M5 x 105
9 - End plate
- Mark position in relation to Generator (GEN) housing
10 - Bearing (drive end)
- Removing/installing ~ Fig. 5
11 - Bearing securing plate
12 - Spacer
13 - Woodruff key
14 - Rotor
- Checking for short to ground ~ Fig. 9
- Checking winding for short or open circuits ~ Fig. 10
15 - Bearing (slip ring end)
- Removing/installing ~ Fig. 5
16 - Stator
- Removing/installing ~ Fig. 6
- Checking for short to ground ~ Fig. 7
- Checking for open circuit ~Fig.8
17 - Screw
- M4 x 20
18 - Diode plate
- Checking ~ Fig. 11
19 - Plastic insulating washer
20 - Plastic grease sleeve
- Always use new sleeve.
21 - Generator (GEN) housing
22 - Voltage regulator
- Removing/installing ~ Fig. 2
- Checking carbon brushes ~Fig. 3
23 - Plastic insulating base
24 - Screw
- M5 x 10
25 - Washer
26 - Spring washer
27 - Washer
28 - Hex nut
- D+, M5, 3 Nm (27 in. lb)
29 - Spring washer
30 - Hex nut
- B+ M8, 16Nm (12 ft lb)
31 - Suppressor
- ~ Fig. 1
32 - Screw
- M5 x 10

Fig. 1 Suppressor Connection:

Terminal B+ arrow

Fig. 2 Voltage Regulator, Removing/Installing:

Voltage regulator can be removed with Generator (GEN).

Fig. 3 Carbon Brushes, Checking:

Length of new carbon bushes: 12 mm (0.47 in.)
Wear limit: 5 mm ± 1 mm (0.2 in. ± 0.0394 in.)

Fig. 4 Generator (GEN) Pulley, Removing/Installing:

- Hold with Allen wrench
Hex nut tightening torque 50 Nm (37 ft lb)

Fig. 5 Bearing, Removing/Installing:

1 - Separating tool, e.g. Kukko 15/0 or 17/0
2 - Puller, e.g. Kukko 18/0

Notes:
- When installing press on over inner ring onto stop.
- Always use new bearing.

Fig. 6 Stator And Diode Plate, Removing/Installing:

- Use long nose pliers to dissipate heat at soldering point arrow.
- Unsolder stator windings.

Fig. 7 Stator - Checking For Short To Ground:

- Press resistance measurement button on tester VAG 1315A.
- Connect cables one after the other to measuring points 1 and 2; 1 and 3; 1 and 4; 1 and 5.
- A resistance in the kilo-ohm range must flash in the display.

Fig. 8 Stator - Checking For Open Circuit:

- Press resistance measurement button on tester VAG 1315A.
- Connect cables one after the other to winding ends 1 and 2; 1 and 3; 1 and 4; 2 and 3; 2 and 4; 3 and 4.
- At each point the reading must be approx. 0 Ohm.
- There is an open circuit when a flashing resistance in the kilo-ohm range appears in the display.

Fig. 9 Rotor - Checking For Short To Ground:

- Press resistance measurement button on tester VAG 1315 A.
- Flashing resistance in kilo-ohm range must appear in display.

Fig. 10 Rotor - Checking Windings For Short Or Open Circuit:

- Press resistance measurement button on tester VAG 1315A.
- Resistance value: 2.8 to 3.0
- Open circuit: Flashing resistance in kilo-ohm range will appear in display.
- Winding short circuit: Resistance value is below specified value.

Fig. 11 Diode Plate Checking:

- Press resistance and voltage measurement buttons simultaneously on tester VAG 1315 A.
- Check positive diodes: Connect black test probe to positive heat sink 1 (corresponds to B+) and red test probe to each of the collective points 2 one after the other.
- Checking negative diodes: Connect red test probe to negative heat sink 3 and black test probe to each collective points 2 one after the other.
- Checking exciter diodes: Connect black test probe to contact rail 4 (corresponds to D+) and red test probe to each collective points 2 one after the other.

For all checks 50-80 must be indicated 3 times. If this is not the case, replace diode plate.