1. Disconnect the 8P connector (A) from the combination switch.
2. Measure the voltage with a voltmeter across the connector B1 terminal and chassis when the main switch is ON position.
3. If the voltage differs from the battery voltage, main switch or wiring harness is faulty.
4. Measure the voltage with a voltmeter across the connector B2 terminal and chassis when the main switch is ON position.
5. If the voltage differs from the battery voltage, check the wiring harness and main switch.