GEAR-RING-YM 2755277 - Caterpillar

Illustration 1 g00873253
Diode Assembly (1) Terminal (2) Terminals
Remove the diode assembly from the alternator.
Set the multimeter to the diode scale.
Connect the multimeter leads across terminal (1) and one terminal (2) .
Record the multimeter reading.
Reverse the multimeter leads.
Record the multimeter reading.Expected Result: One reading is "0L" and the other reading is .4 to .9 volts.Results:OK - One reading is "0L" and the other reading is .4 to .9 volts. The diode is normal. Repeat steps 3 through 6 for the other terminals (2). If all of the diodes are normal, the diode assembly is normal. STOP.NOT OK - Both readings are "00". The diode assembly is shorted. Replace the diode assembly. STOP.NOT OK - Both readings are "0L". The diode assembly is open. Replace the diode assembly. STOP.