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Micro 420 Electrical System Tester

WARNING: This page is about a different car, the 2006 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

The Micro 420 automotive battery system tester is designed to help diagnose the cause of a defective battery. (Refer to ELECTRICAL/BATTERY SYSTEM/BATTERY - STANDARD PROCEDURE - USING MICRO 420 BATTERY TESTER)  for directions on using the Micro 420 battery tester.

BATTERY SYSTEM DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
THE BATTERY SEEMS WEAK OR DEAD WHEN ATTEMPTING TO START THE ENGINE.

1. The electrical system ignition-off draw is excessive.

1. (Refer to ELECTRICAL/BATTERY SYSTEM/BATTERY - STANDARD PROCEDURE - IGNITION-OFF DRAW TEST)  for the proper test procedures. Repair the excessive ignition-off draw, as required.

2. The charging system is inoperative.

2. Determine if the charging system is performing to specifications, (Refer to ELECTRICAL/CHARGING - DIAGNOSIS AND TESTING) . Repair the inoperative charging system, as required.

3. The battery is discharged.

3. Determine the battery state-of-charge using the Micro 420 battery tester, (Refer to ELECTRICAL/BATTERY SYSTEM/BATTERY - STANDARD PROCEDURE - USING MICRO 420 BATTERY TESTER) . Charge the battery as required.

4. The battery terminal connections are loose or corroded.

4. (Refer to ELECTRICAL/BATTERY SYSTEM/CABLES - DIAGNOSIS AND TESTING) . Clean and tighten the battery terminal connections, as required.

5. The battery has an incorrect size or rating for this vehicle.

5. (Refer to ELECTRICAL/BATTERY SYSTEM - SPECIFICATIONS)  for the proper size and rating. Replace an incorrect battery, as required.

6. The battery is inoperative.

6. Determine the battery cranking capacity using the Micro 420 battery tester, (Refer to ELECTRICAL/BATTERY SYSTEM/BATTERY - STANDARD PROCEDURE - USING MICRO 420 BATTERY TESTER) . Replace the inoperative battery, as required.

7. The starting system is inoperative.

7. Determine if the starting system is performing to specifications, (Refer to ELECTRICAL/STARTING - DIAGNOSIS AND TESTING) . Repair the inoperative starting system, as required.

8. The battery is physically damaged.

8. Inspect the battery for loose terminal posts or a cracked and leaking case. Replace the damaged battery, as required.

THE BATTERY STATE OF CHARGE CANNOT BE MAINTAINED.

1. The battery has an incorrect size or rating for this vehicle.

1. (Refer to ELECTRICAL/BATTERY SYSTEM - SPECIFICATIONS)  for the proper size and rating. Replace an incorrect battery, as required.

2. The battery terminal connections are loose or corroded.

2. (Refer to ELECTRICAL/BATTERY SYSTEM/CABLES - DIAGNOSIS AND TESTING) . Clean and tighten the battery terminal connections, as required.

3. The electrical system ignition-off draw is excessive.

3. (Refer to ELECTRICAL/BATTERY SYSTEM/BATTERY - STANDARD PROCEDURE - IGNITION-OFF DRAW TEST)  for the proper test procedures. Repair the inoperative electrical system, as required.

4. The battery is inoperative.

4. Test the battery using the Micro 420 battery tester, (Refer to ELECTRICAL/BATTERY SYSTEM/BATTERY - STANDARD PROCEDURE - USING MICRO 420 BATTERY TESTER) . Replace the inoperative battery, as required.

5. The starting system is inoperative.

5. Determine if the starting system is performing to specifications, (Refer to ELECTRICAL/STARTING - DIAGNOSIS AND TESTING) . Repair the inoperative starting system, as required.

6. The charging system is inoperative.

6. Determine if the charging system is performing to specifications, (Refer to ELECTRICAL/CHARGING - DIAGNOSIS AND TESTING) . Repair the inoperative charging system, as required.

7. Electrical loads exceed the output of the charging system.

7. Inspect the vehicle for aftermarket electrical equipment which might cause excessive electrical loads.

8. Slow driving or prolonged idling with high-amperage draw systems in use.

8. Advise the vehicle operator, as required.

THE BATTERY WILL NOT ACCEPT A CHARGE.

1. The battery is inoperative.

1. Test the battery using the Micro 420 battery tester, (Refer to ELECTRICAL/BATTERY SYSTEM/BATTERY - STANDARD PROCEDURE - USING MICRO 420 BATTERY TESTER) . Replace the inoperative battery, as required.