GM Service Manual Online
For 1990-2009 cars only
  1. Visually inspect the hydrometer (built into the battery) for the following conditions:
  2. • Green eye - battery is charged.
    • Dark eye - battery is discharged. Charge and load the test battery. Refer to Battery Load Test .
    • Clear or light yellow eye - battery electrolyte is low. Replace the battery. Refer to Battery Replacement .
  3. Ensure that the generator connector and the generator BAT terminals are both clean and tight.
  4. Ensure that the battery connections are clean and tight.
  5. Check the serpentine belt.
  6. Important: Perform the On-Board Diagnostic System Check to be certain no diagnostic trouble codes are stored in memory which, if ignored, may lead to a misdiagnosis. Refer to Powertrain On Board Diagnostic (OBD) System Check .

  7. Check for proper installation of the aftermarket electronic equipment which may affect the integrity of other systems. Refer to SECTION 8A-4.