How to Test a 1993 Mustang Alternator
- 1). Raise the Mustang's hood. Locate the battery, which is on the driver's side near the front fender in the engine compartment. Remove the battery cover to expose the terminal posts.
- 2). Connect a voltmeter to the battery posts before cranking the engine. Attach the positive test lead first. Connect the negative test lead. The positive battery post has a red connector and a plus sign (+) next to it. The negative post has a black connector and a negative sign (-) beside it.
- 3). Note the reading displayed by the voltmeter before the engine is cranked. That is the battery reading, and it should be between 12.5 and 12.8 volts, if the battery is healthy. Even a perfect alternator can't recharge a dead battery.
- 4). Crank the Mustang. Note the voltmeter reading again. The voltmeter is measuring the voltage of the alternator, which supplies the power to the battery when the engine is running. The reading should be between 13.6 and 14.3 volts.
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