Sakai SW354, Shop Manual

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10-003
TROUBLESHOOTING
2. ELECTRICAL SYSTEM TROUBLESHOOTING
2-1. When Performing Electrical System Fault Diagnosis
WARNING
Be very careful because equipment can return to normal during an inspection and suddenly operate
properly when a failure occurs due to a faulty contact or other such cause.
2-1-1. Precautions to take during electrical circuit fault diagnosis
When disconnecting or connecting a connector, be sure to turn the power supply OFF. (Electronic control parts
such as the engine control unit, in particular, could be damaged internally.)
Since connectors are not numbered, be sure to affix alignment marks so that you can restore them to their
original condition.
Before making a diagnosis, check related connectors for faulty connections. (Check by disconnecting and
reconnecting related connectors several times.)
Before proceeding to the next step, be sure to return the disconnected connectors to their original condition.
When diagnosing a circuit (measuring the voltage, resistance, continuity and current), move related wiring and
connectors several times, and check whether the tester’s numerical values change. (If values change, faulty
contact in the circuit is possible.)
Do not ground the circuit of the control unit or apply voltage to it unless otherwise specified.
For information of wire number, wire size, and wire color used in the sample circuit diagrams, refer to "1-1. Wire
Numbers, Wire Sizes, Wire Colors and Connectors Shown in Electrical Circuit Diagram, Wiring Harness Layout
and Wiring Harnesses" (P.5-001).
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