ALTERNATOR GP 2741342 - Caterpillar

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 16.Test Step 15. 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 an ammeter between the disconnected battery ground cable and one of the negative battery terminals. Connect the red positive lead of the ammeter to the cable. The negative lead should be connected to the battery terminal. If a multimeter is being utilized for this test, 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 (ECM) 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 A (50 mA).Results:
YES - The current is below 0.050 A. The charging system is currently good. The problem is a possible intermittent current draw in the system. The batteries may have failed. 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 16.Test Step 16. TEST THE CURRENT OF THE ALTERNATOR OUTPUT BELOW 2 A.
Turn the keyswitch to the OFF position.
Connect the 9U-5795 Current Probe or 8T-0900 Ammeter to a DMM (digital multimeter). Clamp the probe around the "B+" wire of the alternator. Before you clamp the probe around the wire, ensure that the probe is "zeroed".
Read the current on the meter. Make a note of the current that was measured.Expected Result:The current is under 2 A.Results:
YES - The current is under 2 A. Proceed to test step17.
NO - The current is over 2 A.Repair: There is an internal problem with the alternator. Repair or Replace