1. Disconnect the 8P connector (A) from the combination switch.
2. Set the light switch to the OFF position.
3. Measure the resistance with an ohmmeter across the B1 terminal to the T terminal, the B1 terminal to the 1ย ย ย ย ย ย ย ย ย terminal and the B1 terminal to the 2 terminal.
4. If infinity is not indicated, renew the combination switch.