Basic Electrical Component Handling / Precautions for Vehicles Equipped with Computer Controlled Systems

• Never disconnect the batteries while the key switch is on and the engine is running. Why: This can cause electrical voltage spikes that can damage electronic components.
• Do not connect jumper cables while the key switch is on. Why: This can cause electrical voltage spikes that can damage electronic components.
• Disconnect batteries prior to recharging (if possible) Why: Electrical loads in the machine can slow the recharging process. Battery chargers can cause electrical voltage spikes that can damage electronic components.
• Never jump start the machine with a voltage higher than the machine is designed to operate on Why: This can damage electronic components
• Do not connect or disconnect electrical connectors while the key switch is on or the machine is running.

  Why: This can cause computer system errors from interrupting a computer program while it is running and electrical voltage spikes that are produced can damage electronic components.

• Do not apply power or ground to any component as a test unless specifically instructed to do so. Why: Connecting the wrong voltage to the wrong point of an electronic system can cause electronic component failures.
• When welding on the machine, make sure to connect ground lead to the parts being welded. For maximum protection disconnect all electronic controllers before welding. Why: The high currents associated with welding can damage wiring harnesses that are involved in the ground path. Welding can also cause electrical voltage spikes that can damage electronic components.