ALTERNATOR G 2P8672 - Caterpillar

Procedure To Detect A Failure Of The CR11 Suppressor Diode.
1. Shut the engine down and be sure there is no voltage on the generator.2. Check the temperature of the suppressor. If it is hot to the touch it is probably defective. Use the illustrations and Step 3 to check the suppressor.3. To test the suppressor it is necessary to apply AC voltage to the suppressor circuit. Illustration 1 shows the test using 120 Volt AC current to activate the suppressor. Illustration 2 shows the test using 240 Volt AC current to activate the suppressor. The chart shows the appropriate voltage to use for each suppressor and voltage regulator.
Illustration 1. Test using 120 Volt AC current.
Illustration 2. Test using 240 Volt AC current.When the light bulb(s) are connected and voltage is applied, the bulbs should not light. If the bulb(s) light, even dimly, the CR11 Suppressor Diode being tested is defective and should be replaced.