Energize the circuit with the fuel tank selector switch selected to the left-hand position. Using the schematic, identify the switches that will change position.

Energize the circuit with the fuel tank selector switch selected to the left-hand position. Using the schematic, identify the switches that will change position.

• A. 1, 2, 3
• B. 5, 6, 11, 12, 13, 15, 16
• C. 4, 7, 8, 9
• D. 10, 14, 17

Answer: (B)

When a selector switch moves to a position, it feeds power to a specific set of relay coils, which then cause their associated contacts to switch state. In this schematic, selecting the left-hand fuel tank position energizes the coil circuits that control the contacts for the switches numbered 5, 6, 11, 12, 13, 15, and 16. Once those coils receive current, their contacts change state (closing normally open contacts or opening normally closed contacts), reconfiguring the circuit paths accordingly. The remaining switches aren’t energized by the left position, so their contacts stay in their current states. This is why those particular switches are the ones that change.

When a selector switch moves to a position, it feeds power to a specific set of relay coils, which then cause their associated contacts to switch state. In this schematic, selecting the left-hand fuel tank position energizes the coil circuits that control the contacts for the switches numbered 5, 6, 11, 12, 13, 15, and 16. Once those coils receive current, their contacts change state (closing normally open contacts or opening normally closed contacts), reconfiguring the circuit paths accordingly. The remaining switches aren’t energized by the left position, so their contacts stay in their current states. This is why those particular switches are the ones that change.