Engine cannot be started, and host power cannot be cut off？

Failure Phenomenon

There is a PC200-8 machine, which has been maintained on time. Recently, it was found that the engine of the machine cannot be started, and the power of the host machine cannot be cut off. In addition, the display shows an abnormality.

Fault Check

1. On-site inspection, it was found that the machine display prompts a G043 fault code, and the excavator operation has a phenomenon that the engine oil pressure drops and the engine speed sensor is abnormal;

2. Analysis Because the power cannot be cut off, it is necessary to adjust and check the electrical system of the excavator.

Malfunction Repair

1. Remove the 3P plug of the battery relay to cut off the power;

2. Unplug the 5A fuse for F-2 relay & timer, which can cut off the power;

3. Unplug the alternator relay to cut off the power;

4. The inspection found that the 2P plug of the alternator was not connected well;

5. After the 2P plug of the alternator is plugged in, it becomes normal.

Fault summary

1. When the flame is off, the regulator inside is not grounded, causing the alternator relay not to be pulled in. The alternator relay has been supplying power to the battery relay, so he cannot cut off the power;

2. When the engine cannot be started, the throttle can be added to the normal tube key, and the throttle can also go to the flameout position, but as soon as the car is turned off, the throttle will not reach the flameout position.