An engine's alternator charges the battery when you drive. The alternator on the 2003 Toyota Corolla is located on the left front side of the engine next to the tension pulley and above all of the other engine pulleys. Replacing the alternator on this car is time-consuming, but you don't need extensive knowledge of the engine to complete the replacement. You can buy the replacement alternator and rent tools, if needed, at almost any auto parts supplier.
Open the hood and loosen the screw that secures the positive battery cable to the battery using the wrench. Pull the cable off the battery to avoid shock.
Connect the adjustable wrench to the metal arm on the tension pulley. Pull the wrench toward the radiator and remove the drive belt from the roller on the tension pulley.
Connect the socket to the ratchet and remove the upper and lower bolts on the side of the alternator. Pull the alternator off the engine. Connect the engine pulley remover to the power drill. Insert the tip on the puller to the nut on the center of the alternator's pulley. Use the power drill to remove the nut and then pull the pulley off the alternator.
Secure the pulley to the new alternator the opposite way that you removed it. Place the new alternator in the engine in the same place as the old alternator. Replace the bolts and tighten the bolts using the ratchet and socket.
Replace the drive belt to the alternator's pulley. Pull the wrench toward the radiator and replace the belt to the tension pulley. Remove the wrench from the tension pulley and close the hood.
