Test Step 12. MEASURE THE CURRENT OF THE SYSTEM BY REMOVING THE NEGATIVE BATTERY CABLE.
- Disconnect the ground cable from the negative battery post. There may be more than one battery that is connected to ground. Disconnect all of the batteries that are connected to ground. Do not disconnect cables that are between batteries that are connected in series.
- Connect a multimeter between the disconnected battery ground cable and one of the negative battery terminals. Connect the red positive lead of the multimeter to the cable. The negative lead should be connected to the battery terminal. Use the 10 A connections in order to avoid damage.
Note: The standard acceptable current draw is 50 mA. A current draw above 50 mA usually indicates a problem. However, some large machines with multiple electronic control modules have a higher acceptable limit. For more information, contact a Caterpillar dealer or contact the business unit that produces the machine.
Expected Result:
The current is below .050 amperes (50 mA).
Results:
- YES – The current is below 0.050 A. The charging system is currently good. The fault is possibly an intermittent draw in the system. The batteries may be faulty. Check that NO accessories were ON during the test.STOP
- NO – The current is above 0.050 A. There is excessive current flow in the system. Proceed to test step 13.