During an exterior vehicle inspection, a rear stop light is found to be inoperative. Technician A says a blown bulb could be the cause. Technician B says that poor connection at the bulb socket could be the cause. Who is right?

The correct answer is that both Technician A and Technician B are right because both a blown bulb and a poor connection at the bulb socket can lead to an inoperative rear stop light.

When a bulb is blown, it breaks the circuit, thus preventing electricity from flowing through, which means the stop light will not illuminate. This is a common issue and can often be the first thing checked during an inspection due to its straightforward nature.

On the other hand, a poor connection at the bulb socket can also cause the rear stop light to be inoperative. If the connection is corroded, loose, or dirty, it may not establish a complete electrical circuit even if the bulb itself is functioning properly. Therefore, it is essential to check not only the bulb but also the connections and wiring to ensure proper operation.

Both factors can contribute to the malfunction, highlighting the need for a thorough inspection to diagnose the problem accurately.