Verify that the alternator “B+” terminal nut is tight and verify that the wire has a good connection to the “B+” terminal. Many Caterpillar machines…

T2a – Undesired Electrical System Current – Test (For Machines Equipped With a Main Disconnect Switch) Turn off all of the accessories. Turn the keyswitch…

Ensure that the batteries are NOT fully charged. Fully charged batteries have open circuit voltage above 12.5 V on 12 V systems or 25 V…

CHECK THE SYSTEM VOLTAGE. Before you start the machine, connect a voltmeter between the “B+” terminal and the case of the alternator. Turn OFF all…

Often when problems with the charging system are being investigated, the alternator is not the problem. If a low battery condition is present, test the…

Stator Check the resistance that is between each of the phases. Measure the resistance between the end of each lead wire and neutral point. The…

Verify that the nut for the “B+” terminal is tight. Verify that the wire has a good connection to the “B+” terminal. Many Caterpillar machines…

Make sure that every electrical component is turned OFF. Make sure that the keyswitch is turned OFF. Make sure that the dome lights are OFF.…

Reference: Service Magazine, SEBD1672 July 1986, “Brushless Alternators May Not Charge In Certain Conditions” Start the engine and set the throttle to at least 75%.…

Turn the keyswitch to the OFF position. Connect the 9U-5795 Current Probe to a DMM (digital multimeter) or use a 225-8266 Ammeter Tool Gp .…