Generator mounting elements
1 - adjusting bolt; 2 - generator 90 A; 3 - bolt, 20–25 Nm; 4 - bolt, 20–28 Nm; 5 - bracket; 6 - bolt, 12–15 Nm; 7 - bolt; 8 - generator 75 A; 9 - adjusting bolt; 10 - bolt, 20–25 Nm.
Withdrawal
1. Disconnect the negative battery cable and connectors from the radiator fan and condenser fan.
2. Turn out bolts of fastening of a radiator.
3. Loosen the belt tension adjusting bolt and remove the alternator mounting bolt. Raise the vehicle.
4. Disconnect the connector from the generator and the wire from the B+ terminal of the generator.
5. Turn out a bolt and nuts of fastening of the generator. Raise the radiator and remove the alternator from the vehicle.
Disassembly (75 A)
Warning! Install soft protective pads on the vice jaws to prevent damage to the generator parts.
1. Secure the alternator in a vise and remove the three pinch bolts.
2. Insert the blade of two flathead screwdrivers between the front cover and the stator core and remove the cover.
Warning! Do not insert screwdrivers too deep as the stator winding may be damaged.
Warning! The rear cover may be difficult to remove due to the use of a ring that secures the rear bearing outer race. To make it easier to remove the back cover, heat it with a 200W soldering iron. Do not use a hair dryer for heating, as the diode block may be damaged.
3. Secure the rotor on the pulley side in a vise.
4. Remove the pulley nut, then remove the spring washer, pulley and spacer.
5. Remove the front cover and two washers.
6. Remove the rotor from the vise.
7. Remove the screws securing the brush holder, rectifier and terminal B nuts.
8. Remove the stator from the rear cover.
9. Separate the oil deflector from the brush holder.
10. Unsolder the three wires from the diodes and remove the stator.
Warning! Desoldering should be carried out for no more than 5 s, otherwise the rectifier diodes may be damaged.
11. When separating the rectifier from the brush holder, desolder the two plates soldered to the rectifier.
Examination (75 A)
Rotor
1. Measure the resistance between the slip rings with an ohmmeter. If the resistance is extremely low, then there is a short circuit in the rotor winding. If there is no conductivity, then there is a break in the rotor winding, and the rotor must be replaced.
Resistance: 3.1 ohm
2. Using an ohmmeter, check the continuity between the slip ring and the armature of the rotor. If there is continuity, replace the rotor.
Stator
1. Using an ohmmeter, check the continuity between the wires of the stator coil. If there is no continuity, replace the stator.
2. Check the continuity between the stator coils with an ohmmeter. If there is continuity, replace the stator.
Checking the rectifier unit
1. Check for continuity between the positive poles of the rectifier and the stator coil lead terminal. The ohmmeter should only show conductivity in one direction. If there is conductivity in both directions, then the diode is broken and the rectifier must be replaced.
2. Check for continuity between the negative poles of the rectifier and the stator coil lead terminal. The ohmmeter should only show conductivity in one direction. If there is conductivity in both directions, then the diode is broken and the rectifier must be replaced.
3. Using an ohmmeter, check the continuity between the terminals of each of the three diodes. The ohmmeter should only show conductivity in one direction.
If there is conductivity in both directions, then the diode is broken and the rectifier must be replaced.
Brush replacement
1. If the brushes are worn to the maximum allowable length, replace them.
2. Unsolder the braided wire and remove the spring and brush.
3. Install the brush spring and new brush into the brush holder.
4. Insert the brush so that there is a distance of 2–3 mm between the wear limit line and the end face of the brush holder.
5. Solder the braided wire to the brush holder.
Disassembly (90 A)
1. Loosen the terminal nuts "IN" to the back cover.
2. If it is necessary to remove the stator, unsolder the four stator wires from the rectifier diodes.
Warning! Desoldering should be carried out for no more than 5 s, otherwise the rectifier diodes may be damaged.
3. Remove the stator from the rear cover.
4. Remove the brush holder and straightener.
5. Turn out four coupling bolts.
6. Insert the blade of two flathead screwdrivers between the front cover and the stator core and remove the cover.
Warning! Do not insert screwdrivers too deep as the stator winding may be damaged.
Warning! The rear cover may be difficult to remove due to the use of a ring that secures the rear bearing outer race. To make it easier to remove the back cover, heat it with a 200W soldering iron. Do not use a hair dryer for heating, as the diode block may be damaged.
7. Secure the rotor on the pulley side in a vise.
Warning! Install soft protective pads on the vice jaws to prevent damage to the generator parts.
8. Remove the pulley nut, then remove the spring washer, pulley and spacer.
9. Remove the front cover and washers.
10. Remove the rotor from the vise.
11. When separating the rectifier from the brush holder, unsolder the two plates from the rectifier.
Examination (90 A)
Rotor
1. Measure the resistance between the slip rings with an ohmmeter. If the resistance is extremely low, then there is a short circuit in the rotor winding. If there is no conductivity, then there is a break in the rotor winding, and the rotor must be replaced.
Resistance: 3.1 ohm
2.Using an ohmmeter, check the continuity between the slip ring and the armature of the rotor. If there is continuity, replace the rotor.
Stator
1. Using an ohmmeter, check the continuity between the wires of the stator coil. If there is no continuity, replace the stator.
2. Check the continuity between the stator coils with an ohmmeter. If there is continuity, replace the stator.
Checking the rectifier unit
1. Check for continuity between the positive poles of the rectifier and the stator coil lead terminal. The ohmmeter should only show conductivity in one direction. If there is conductivity in both directions, then the diode is broken and the rectifier must be replaced.
2. Check for continuity between the negative poles of the rectifier and the stator coil lead terminal. The ohmmeter should only show conductivity in one direction. If there is conductivity in both directions, then the diode is broken and the rectifier must be replaced.
3. Using an ohmmeter, check the continuity between the terminals of each of the three diodes. The ohmmeter should only show conductivity in one direction. If there is conductivity in both directions, then the diode is broken and the rectifier must be replaced.
Assembly
1.Assembly is carried out in the reverse order of disassembly, taking into account the following.
2.Before attaching the rotor to the back cover, insert the wire through the small hole in the back cover to lock the brushes in the retracted position. After installing the rotor, remove the wire.
Installation
1. Install the generator to the engine. Insert the central alternator mounting bolt, but do not screw the nut onto it.
2. Move the generator to one side along the central generator mounting bolt and measure the distance between the generator support and the bracket.
3.Choose a set of spacer washers that matches the measured distance.
4. Insert the spacers and screw the nut onto the central alternator mounting bolt. Further installation is carried out in the reverse order of removal.