What does a high resistance reading on a dead-open circuit indicate?

• A. The circuit is functioning normally.
• B. The battery is fully charged.
• C. The fuse is blown.
• D. A broken wire or poor connection with a disconnected circuit path.

Answer: (D)

High resistance on a dead-open circuit means there is no complete path for current to flow. When the circuit path is broken or a connection is loose, the meter can’t establish conduction, so the reading climbs to very high (essentially infinite) resistance. That’s why the most likely cause is a broken wire or a poor connection that disconnects the circuit path. If the circuit were functioning normally, you’d expect a low, continuous resistance. A fully charged battery doesn’t remove the open condition, and while a blown fuse also creates an open circuit, the specific clue here is an actual disconnected path—i.e., a broken wire or loose connection.