How to Replace an Alternator on a 2003 Toyota Camry S

Bring your original alternator to the parts store to make sure the replacement matches.

The alternator in a car generates the power needed to keep the battery charged and operate the electrical system. It produces alternating current, which the diode rectifiers convert to direct current. The alternator on a 2003 Toyota Camry is mounted on the front of the engine and is driven by a belt connected to the crankshaft. A voltage regulator inside the alternator controls the output. The alternator should produce between 13.5 and 15 volts with the engine running at idle.

Things You'll Need

• Fender cover or blanket
• Wrenches
• Ratchet
• Sockets
• Alternator

Instructions

Removal

1. Cover the right fender with a fender cover or an old blanket. Remove the negative battery cable.

2. Loosen the upper and lower alternator mounting bolts. Loosen the belt adjustment bolt until you can remove the drive belt from the pulley.

3. Unplug the harness, remove the nut holding the single wire to the alternator and remove the wire from the stud.

4. Remove the upper and lower mounting bolts holding the alternator to the engine. Remove the alternator from the engine.

Installation

1. Position the replacement alternator on the engine and thread the upper and lower mounting bolts in hand-tight.

2. Connect the harness. Place the single wire over the stud and tighten the nut.

3. Install the drive belt onto the pulley. Tighten the adjuster bolt until the belt can only be moved about a 1/4 inch when you push on it halfway between the pulleys. Tighten the alternator mounting bolts.

4. Connect the negative battery cable. Check the voltage output with a voltmeter.

Tips & Warnings

• Bring your original alternator to the parts store to make sure the replacement matches.

• Some new and remanufactured alternators come without a pulley. Most parts stores will swap the pulley from the old to the replacement for you.

• Alternators are expensive. Before you buy one, perform the following checks: verify that the drive belt is not loose, make sure that the battery terminals and posts are not loose or corroded, check that the harness and single wire are securely connected to the alternator, test each cell on the battery with a hydrometer, make sure the battery is fully charged and check the voltage with the engine running at idle.

References

• "Haynes Repair Manual: Toyota Camry 2002-2006"; Jay Storer, John Haynes; 2009