Test Step 11. MEASURE THE CURRENT OF THE SYSTEM BY USING THE MAIN DISCONNECT SWITCH.
- Turn the disconnect switch to the ON position.
- Connect a multimeter across the disconnect switch terminals. Connect the red lead to the terminal on the frame side. Connect the black lead to the terminal on the battery side. Use the 10A connections in order to avoid damage.
- Turn the disconnect switch to the OFF position and read the current. Make a note of the measured current.
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 0.050 A (50 mA).
Results:
- YES – The current is below 0.050 A. The charging system is functioning properly at this time. The failure is possibly an intermittent draw in the system. The batteries may have failed. Ensure that NO accessories were ON during the test. Exit this procedure and retest the alternator charging system.STOP
- NO – The current is above 0.050 A. There is a draw in the system. Proceed to test step 13.