Hitachi Excavator Repair Guide: Precautions for Inspection and Maintenance of Hitachi Excavator

This illustration show the precautions for inspection and maintenace for Hitachi excavator.

Related Contents:

IMPORTANT
Do not turn OFF battery disconnect switch (1) while the engine is running and the key switch is in the position other than OFF. And do not turn OFF battery disconnect switch until more than five minutes past after stopping the engine. Failure to do so may damage the electrical system.

IMPORTANT
After stopping the engine, the DEF pump continues to be operated for a specified time in order to return DEF from the hose to the DEF tank. Do not set the battery disconnect switch to the OFF position while battery disconnect switch indicator (2) is lighting.

1. Disconnect the power source: Set battery disconnect switch (1) to the OFF position first when taking off wire harnesses and connectors for repair or replacement work. Failure to do so can result in damage to the wire harnesses,fuses and fusible links and, in some cases, cause fire due to short circuiting. In addition, even when the key switch is set to the OFF position, the controller may be operated for a specified time. Therefore, set battery disconnect switch
(1) to the OFF position after setting the key switch to the OFF position and waiting five minutes or more.

2. Color coding of wire harnesses: As for the color codes of wire harnesses in the electrical system, refer to the table. If one wire harness consists of two colors, two or more codes are indicated. The left code stands for base color and the right code stands for marking color.

NOTE
• Code BW indicates a black base wire harness with white fine-line marking.
• Initials "O" and "Or" both stand for the color orange.
• Longitudinal stripes printed on wires are not color code and indicate the kinds of wires
3. Precautions for connecting and disconnecting terminal connectors:
• Disconnect the connectors by grasping. Do not pull on the wire harness itself. Release the lock first before attempting to separate the connectors, if a lock is provided.(Refer to "Instructions for Disconnecting Connectors"T5-1-7)

The water-resistant connectors keep water out. If water enters them, water will not easily drain from them. When checking the water-resistant connectors, take extra care not to allow water to enter the connectors. In case water should enter the connectors, reconnect only after the connectors are thoroughly dried.
• Before connecting the connectors, check that no terminals are bent (3) or coming off (4). In addition, as most terminals are made of brass, check that no terminals are rusting (2)

4. Precautions for using a circuit tester:
• Before using a circuit tester, refer to the instructions in the circuit tester manual. Then, set the circuit tester to meet the object to be measured, voltage range and current polarity.
• Before starting the connector test, always check the connector terminal numbers by referring to the circuit diagram. When the connector terminal size is very small, and the standard test probe size is too large to be used for testing, wind a fine piece of sharpened wire or a pin around the test probe to make the test easier.
• When checking the connector by using a circuit tester, do not damage the terminal inside the connector. Insert a test probe from the wire harness end of the connector.