An alternator provides an electrical charge to a vehicle's battery so that it can be used to start the vehicle. Over time the internal contact points that transfer the charge, called the brushes, wear out. Replacing an alternator can be an expensive option, especially if it is a dealer-only item for your particular vehicle. Rebuilding an alternator with a rebuild kit can save a lot of money for the home DIY mechanic who wants to invest a little time instead of cash.
Disconnect the negative cable from the car battery. Loosen the alternator mounting bracket bolts, one on top and bottom of the alternator. Slide the alternator towards the motor so you can slip the belt off the pulley. Remove the wires connected on the back of the alternator, remembering where they go or labeling for future reference. Remove the mounting bolts and pull out the alternator.
Remove the voltage regulator from the alternator. The voltage regulator will appear like a small button on the back of the alternator. Two small nuts or bolts will be holding it in place. Be prepared to catch any parts that come off because of the pressure from the springs located behind the brushes.
Replace the brushes on the voltage regulator. Carefully remove the worn brushes, taking care not to lose the internal push springs. Replace the brushes one at a time through the opening provided in the voltage regulator housing, using a toothpick to hold them in place.
Install the voltage regulator back onto the alternator. Carefully place the voltage regulator in place and attach to the alternator using the bolts or nuts previously removed in Step 2. Once the voltage regulator is firmly in place, remove the toothpicks used in Step 3.
Install and reconnect the alternator. Installation is the opposite of removal. Insert the bottom bracket bolt first and align with the alternator. Do not tighten completely yet. Align the top of the alternator with the top bracket and insert the top bolt. Pull the alternator belt back into the pulley groove on the alternator. Using a long screwdriver or wrench as a pry bar, put force on the alternator just behind the bracket to put maximum tension on the alternator belt. Tighten the top bolt of the alternator. Release the tension and tighten the bottom bolt on the alternator.
Reconnect the wires to the back of the alternator. Reconnect the negative battery cable. You will need to reset any clocks or radio presets.
