Parasitic Load Testing

TOOL REQUIRED:
J 39200 Digital Multimeter
1. Turn the ignition to LOCK.
2. Charge the battery to a full state of charge. Refer to "Battery Charging". Service and Repair
3. Disconnect the negative (-) battery cable.

Parasitic Load Test With Ammeter:

4. Connect an ammeter capable of carrying at least 20 amperes in series between the negative (-) battery terminal and the negative (-) battery cable.
Measure
^ Parasitic load draw (in amperes) with all doors closed and the ignition switch in the LOCK position.
5. If a parasitic load drain over 0.5 amperes is present, isolate the electrical system, circuit or component at fault through the following procedure:
A. Remove fuses one at a time. Refer to Fuse Block Details for electrical system schematics, system diagnosis, component location views and wiring repair procedures. If a parasitic load drain over 0.5 amperes is still present, proceed to step B.
B. Check the starter motor, starter solenoid and related wiring for short circuits. Refer to Charging System for generator and charging system diagnosis. Charging System

Parasitic Load Test With J 39200 Digital Multimeter:

6. If a parasitic load drain less than 0.5 amperes is present, disconnect and remove the ammeter and connect a J 39200 between the negative (-) battery terminal and the negative (-) battery cable. Set the selector switch to Milliamp/Microamp Input Terminal scale.

NOTE: To prevent possible damage to the J 39200, do not open any doors or operate any equipment that would draw more than 10 amperes. If the fuse opens, replace it with a 10 ampere fast opening fuse. Failure to use the proper fuse may result in damage to the J 39200.

Measure
^ Parasitic load draw (in milliamperes) with all doors closed and the ignition switch in the LOCK position.
7. Normal parasitic load drain is 10 to 25 milliamperes. If the parasitic load drain is more than 25 milliamperes, isolate the electrical system, circuit or component at fault through the following procedure:
A. Remove fuses one at a time. Refer to Fuse Block Details for electrical system schematics, system diagnosis, component location views and wiring repair procedures. If a parasitic load drain over 25 milliamperes is still present, proceed to step B.
B. Check the starter motor, starter solenoid and related wiring for short circuits. Refer to Cranking System for starter motor and starter solenoid diagnosis and repair procedures.

Important: Repeat parasitic load test procedure after any electrical repair has been completed.

8. When the cause of the excessive parasitic load drain has been located and repaired, disconnect and remove the J 39200 and connect the negative (-) battery cable.
Tighten
^ Negative (-) battery cable-to-negative (-) battery terminal retainer to 5.5 N.m (48.68 lb. in.).