96 Century

[Charley]

How do I know if Alternator is bad? Is there any sure way to tell? Thanks.

[Scott K]

What engine is in it? 4cyl or 6cyl? Check for power at the red wires, and check for a wire that turns on and off with the key.

Most larger parts stores will have a tester to see if it is charging.

[Jeremy airjer W]

Check for charging voltage at the battery. You Should see more than 14 volts. If there is 12.5 or less than check for charging voltage at the back of the alternator. If the voltage is the same turn off the engine then turn the key to the run position. Unplug the small connector from the back of the alternator. One of the wires should have battery voltage. If all the above is correct than the alternator is not working.

[Charley]

Thanks for the help. I checked the voltage at the battery and the reading was 14.2. From what you said that means the alternator is good.

[Scott K]

Sounds like it is charging.