Failure details:
A Cat 336 excavator that has been working for 7400 hours has the phenomenon that the monitoring panel of the excavator is darkened and can not be seen clearly during construction.
Failure analysis:
How to diagnose the fault of the alternator, generally speaking, when the alternator is generating electricity, the alternator indicator should be kept in the off state. When the excavator engine is running, if the alternator indicator is on, the alternator may be faulty.
Troubleshooting ideas:
1. Stop the engine. Turn the key switch to the ON position. Confirm that the alternator indicator is on.
2. Then, start the engine and measure the voltage it emits while the alternator is rotating. As mentioned above, measure the voltage between the terminals next to the alternator. If the voltage is around 28V, the alternator is working properly. If the rated voltage is not issued, the alternator or voltage regulator is faulty.
3. Measure the voltage between the terminals of the alternator. If the measured voltage is around 24V, the alternator circuit can be considered normal. If the measured voltage is low, the cause of the failure may be insufficient battery capacity or loose wire connections. When the voltage is zero volts, the wires between the fuse box and the alternator are loose or open.
In addition, if the ground wire is broken, the alternator cannot generate electricity.
