Voltage Drop Check of the Wire Connecting the Battery to the Alternator

This check determines whether the connection between alternator terminal "B" and the battery positive terminal is reliable.

Preparation for Check

PROCEDURE

1. Turn the ignition switch ON.
2. Connect a digital voltmeter to alternator terminal "B" and to the battery positive terminal.

Check Condition

PROCEDURE

Start the engine, turn on the headlamps, heater blower and other electrical loads, and read the voltmeter.

Check Result

PROCEDURE

1. The voltmeter should read 0.3 V or less.

2. If the voltage is greater than 0.3 V, the wire is damaged or not securely connected to the alternator and battery terminals.
To check the wire, connect terminal "B" and the battery positive terminal with a fused jumper wire.
Check that the wire connections are secure, and make sure the wire insulation is not melted from overheating.
3. Finally, turn off all electrical loads and stop the engine.