Repairing a generator is not a difficult task, and it is quite within the reach of anyone who knows at least a little about auto repair. The design of the generator on all cars is almost the same and consists of the same elements (although, depending on the manufacturer, some differences are possible). If you want to know how to repair a car generator, then read on.
Step 1. Disconnect the wiring terminals from the battery
Step 2. Remove the air filter for easy access to the generator
Step 3. Label the wires before disconnecting them
Step 4. Disconnect the wires from the generator
Step 5. Remove the alternator drive belt
Step 6. Remove the mounting bolts and note their location
Step 7. Remove the generator
Step 8. Remove the plastic casing from the back of the generator after unscrewing the screws that secure it
Step 9. Assess the condition of the bearing
If it makes noises during rotation and / or backlash, then it must be replaced.
Step 10. If the bearing needs to be replaced, do it now
Step 11. Remove the screw that secures the external resistors
Step 12. Be sure to remember or sketch the location of all electrical wires before disconnecting at least one of them
Step 13. Disconnect the rectifier unit; for this you need to unsolder the wires and unscrew the fastening screws
Step 14. Remove the rectifier unit
Step 15. Install the new rectifier unit and screw in the mounting screws
Solder wires to the block.
Step 16. Screw the special removable screw into the rectifier block to separate the brush block
Step 17. Replace brushes; for this you need to unscrew the fastening screws of each brush assembly
Remove the brushes from their seats.
Step 18. Clean the surface of the rotor that the brushes come in contact with
Step 19. Make sure that the springs of the new brushes are not bent and, being pressed into the seats, push the brushes in a straight line, without distortions
Install new brushes.
Step 20. Remove the voltage regulator
To do this, first unscrew the screw from the lowest brush assembly, and then unscrew the screw that secures the ground wire.
Step 21 Install a new voltage regulator and reverse all mounting screws
Step 22. Using an ohmmeter, check if there are any breaks in the windings and if current will flow through the diodes
Step 23. Replace the plastic shroud and external resistors
Step 24. Install the generator back to the engine
Step 25. Connect all electrical wires to the generator; make sure the connection is correct
Step 26. Install and tension the alternator drive belt
Step 27. Reinstall the air filter and re-check the tension of the alternator drive belt and the tightness of all fasteners
Step 28. Inspect the heat shield located behind the generator and make sure it is installed correctly
Step 29. Connect the wiring terminals to the battery
- Spare parts for the generator are relatively inexpensive. They can usually be found at auto electrical stores. In addition, there are special offices selling remanufactured starters and generators; in most cases, they accept faulty units against the cost of new ones.
- It can be useful to photograph and sketch the location of the wires and fasteners. It is very important to ensure that all terminals and bolts are completely seated correctly.
- Be careful not to overtighten the main wire clamp to the brush block, or you may damage it.
- Before installing a new voltage regulator, coat the back of the regulator with thermally conductive paste.
- Consult your vehicle repair manual for the specifications and design features of your alternator.
- On some generators, the rectifier unit is pressed into the back of the housing.
- Sometimes it is convenient to disconnect and connect one wire at a time so as not to confuse their location.