Ford Mustang (1999-2004) Service Manual: Battery (Diagnosis and Testing)

Special Tool(s)

Micro 490 Digital Battery Analyzer 162-00004

Inspection and Verification

1. Verify the customer concern by operating the system.

2. Visually inspect for obvious signs of mechanical or electrical damage.

Visual Inspection Chart

Mechanical Electrical
  • Battery

  • Battery mounting

  • Battery cables
  • Battery posts

3. If an obvious cause for a concern is found, correct the cause before proceeding to the next step.

4. If the fault is not visually evident, proceed to the pinpoint test.

Pinpoint Tests


Test Step Result / Action to Take

Does the meter read, GOOD BATTERY? RETURN the battery to service. REFER to Section.

Does the meter read, GOODRECHARGE? CHARGE the battery and RETURN to service.

REFER to Section.

Does the meter read, CHARGE & RETEST? Fully CHARGE the battery and RETEST


Does the meter read, REPLACE BATTERY? INSTALL a new battery.

Does the meter read, BAD CELLREPLACE? INSTALL a new battery.

NOTE: No battery with a red test-eye should be replaced. The red eye only means the battery is discharged, not necessarily defective. NOTE: Failure to fully charge the battery before retesting may cause false readings.
  • Verify the battery condition using the Battery Analyzer.
  • Is the battery OK?
    Battery and Cables
    Vehicles are equipped with a 12 volt maintenance-free battery that contains a built-in hydrometer. The hydrometer eye indication is as follows: A green dot means the battery is OK. A yel ...

    Battery Disconnect
    WARNING: Batteries normally produce explosive gases which can cause personal injury. Therefore, do not allow flames, sparks or lighted substances to come near the battery, always shield you ...

    Other materials:

    Crankshaft End Play
    Special Tool(s) Dial Indicator Gauge with Holding Fixture 100-002 (TOOL-4201-C) or equivalent 1. Measure the crankshaft end play. Use a Dial Indicator Gauge with Holding Fixture to measure crankshaft end play. 2. Position the crankshaft t ...

    Component Tests
    Engine Oil Leaks NOTE: When diagnosing engine oil leaks, the source and location of the leak must be positively identified prior to repair. Prior to carrying out this procedure, clean all sealing surface areas with a suitable solvent to remove all tra ...

    Automatic transmission vehicles 1. Remove the flexplate. For additional information, refer to Flexplate in this section. Manual transmission vehicles 2. Remove the flywheel. For additional information, refer to Flywheel in this section. All vehicles 3. Using ...