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How-to » Engine » Starting, Charging & Electrical » How to Replace an Alternator
 Note: This is a general guide for all vehicles.

How to Replace an Alternator

PARTS
  • Alternator
TOOLS
  • Screwdriver
  • Serpentine Belt Tool
STEPS
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Moderate
Safety Tip:
Always wear safety glasses when working on your vehicle. Wear other personal protective equipment (PPE) when necessary, for example latex gloves or closed toe shoes.

1
Open the hood and locate your vehicle's alternator.
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2
Using your digital multi-meter, check the battery voltage. A dead battery will usually have less than 9 volts. This would not be enough power to start most vehicles.
3
To verify that your alternator is bad, make sure your battery is fully charged and can pass a load test.
4
With the good battery installed, connect your digital multi-meter across the battery terminals with the engine turned off. A good battery should read between 12-13 volts.
5
Start your engine and read the digital multi-meter's output. The voltage should rise near 13.5-14.5 volts.
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6
Using an open end wrench, disconnect the battery's negative cable.
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7
Disconnect the power and ground wires on the back of the alternator paying close attention to where each wire connects. Disconnect the wiring harness connector.
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8
Loosen the alternator bracket bolts, and alternator adjusting bolts or alternator belt tensioner so that you can remove the alternator drive belt.
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9
Using the proper size socket and ratchet, remove the alternator mounting bolts, spacer (if equipped), adjusting bolt, lower pivot bolt (if equipped), and the alternator.
10
Install new alternator.
11
Using the proper size socket and ratchet, loosely install the alternator mounting bolts, spacer (if equipped), adjusting bolt and lower pivot bolt (if equipped).
12
Install the alternator belt.
13
Pull the alternator until the alternator belt is tight.
14
Tighten the alternator mounting bolts while gently moving the alternator unit to achieve proper alternator belt tension.
15
Reinstall the power and ground wires to alternator. Install the wiring harness connector.
16
Push down in the middle of the alternator belt to check belt tension. If the alternator belt moves more than a half an inch, it is too loose, adjust the alternator belt to proper tension before proceeding to next step.
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17
Now that the alternator belt has been installed and adjusted, reconnect the negative battery cable. Start the engine and check the battery voltage to verify proper alternator charging.
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18
Turn off the engine and recheck the alternator belt tension. Readjust the alternator belt tension if needed.
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