Precautions for Electrical Circuit Service

Precautions for Electrical Circuit Service

- When replacing a fuse, make sure to use a fuse of the specified capacity. Use of a fuse with a larger capacity will cause a damage to electrical parts and a fire.





- Before disconnecting or connecting connectors, be sure to do either of the following depending on the type of power supply. Otherwise, the electrical parts to which the power is supplied may be damaged.

- Continuous power supply: Disconnect the negative cable from the battery.
- Ignition power supply: Push engine switch to change the ignition mode to "OFF".

- When disconnecting connectors, never pull on the wiring harness. Unlock the connector lock first and then pull the male and female connectors apart by holding them.





- When connecting male and female connectors, also hold connectors and put them together until they lock securely (a click is heard).





- When installing a wiring harness, secure it with clamps so that no slack is left.





- When installing vehicle parts, make sure so that they do not interfere with any wiring harness and they do not catch any wiring harness under them.





- Protect the part of harness which may touch any edge by wrapping it with tape or the like.





- Be careful not to touch the electrical terminals of parts which use microcomputers (e.g. electronic control unit like as ECM, PCM, P/S control module, etc.). The static electricity from your body can damage these parts.





- Never connect any tester (voltmeter, ohmmeter or whatever) to terminals of an electronic control unit when its connector is disconnected. Doing so may cause damage to the electronic control unit.
- Never connect an ohmmeter to an electronic control unit with its connector connected to it. Doing so may cause damage to electronic control unit and sensors.
- Be sure to use only the specified voltmeter / ohmmeter. Otherwise, accurate measurements may not be obtained or personal injury may result. Where no voltmeter type is specified, use a voltmeter with high impedance (M ohms/V minimum) or a digital type voltmeter.
- When taking measurements at electrical connectors using a tester probe, be sure to insert the probe (2) from the wire harness side (backside) of the connector (1).





- When it is impossible to insert a tester probe from the harness side of connector, insert a properly sized male terminal with a lead into the connector and connect the tester probe to the lead as shown. Do not insert the probe directly into the connector, or the female terminal may be deformed.





- When checking connection of terminals, check male terminals for bend, female terminals for excessive opening, and both for locking (looseness), corrosion, dust, etc.
- Before measuring voltage at each terminal, make sure that battery voltage is 11 V or higher. Terminal voltage check at low battery voltage will lead to erroneous results.