With Ammeter, In-Line Test Procedure

Check for current drains on the battery in excess of 50 milliamps with all the electrical accessories off and the vehicle at rest. Current drains can be tested with the following procedure.

WARNING: DO NOT ATTEMPT THIS TEST ON A LEAD-ACID BATTERY THAT HAS RECENTLY BEEN RECHARGED.

CAUTION: Do not crank the engine or operate accessories that draw more than 10A. You could open the fuse in the meter.

NOTE:
- Many computers draw 10 mA or more continuously.
- Use an in-line ammeter between the battery positive or negative post and its respective cable.







1. Insert the test leads in the input terminals.
2. Turn switch to mA/A dc.
3. Disconnect battery terminal and touch probes.
4. Isolate circuit causing current drain by pulling out one fuse after another while reading the display.
5. Current reading will drop when the fuse on the bad circuit is pulled.
6. Reinstall fuse and test components (including connectors) of that circuit to find damaged component(s).

The current reading (current drain) should be less than 0.05 amps. If it exceeds 0.05 amps it indicates a constant current drain which could cause a discharged battery. Possible sources of current drain are vehicle lamps (engine compartment lamp, glove compartment lamp, luggage compartment lamp, etc.) that do not shut off properly.