Charging System Diagnosis Cost
The battery must be fully charged to properly test the alternator. Testing with an inadequately charged battery can lead to the replacement of a perfectly good alternator.
It's not uncommon for batteries and/or alternators to be replaced when they really don't need to be. Any of these parts can cause similar symptoms, so to avoid unnecessary replacement, have the battery, alternator, and battery cables properly tested.
A poorly performing charging system can result in various warning lights to illuminate, starting problems, and emission system test failures.
Learn more about the emission failure issues here>>