When your car's electrical system is on the fritz, check to see if your Chrysler alternator needs replacing. Diagnosing any problems in your electrical system can be tricky, but using a few clever time-saving tricks can help you determine if your Chrysler alternator is failing. First, check if the alternator belts are tight and not slipping. If they are cracked or shiny on the side that faces the alternator pulley, then replace them. Check if the warning (also known as the 'idiot light') is on. Most car electrical systems have an electrical current passing through the filament of the warning light; this energizes a circuit in the alternator to start charging. Another diagnostic test requires using a cheap voltmeter to measure the voltage in the system. To do that, you must start the car, turn off any accessories and rev up your motor. With your voltmeter set to the DC scale, measure the voltage that comes across the battery terminals (both the positive and negative). In most systems, the voltage should read 14 volts; if it is less than 12 volts, then you may have a dying alternator. The alternator has two terminals: the positive output terminal of the alternator, and the alternator housing, which is the alternator's negative (-) terminal. When one of these parts of the alternator begins to fail, it is recommended that you replace the alternator as a unit, instead of trying to diagnose and replace each part as they fail.