What are typical consequences of a loose connection in an aircraft electrical circuit?

• A. Increased resistance, heat, potential arcing, and intermittent operation
• B. Decreased resistance and cooler operation
• C. Immediate fuse blow
• D. Higher voltage across the load

Answer: (A)

A loose connection increases the resistance at the contact point. That extra resistance causes power to be dissipated as heat (P = I^2R), so the connection can overheat and damage insulation or nearby components. The poor contact can also arc as vibration causes the connection to intermittently separate and reclose, which is common in aircraft where vibrations are frequent. As the contact quality changes with temperature and movement, the circuit may operate intermittently. Because of the added resistance, the load may see a lower voltage rather than a higher one, and a loose connection does not typically cause an immediate fuse blow. It also doesn’t produce cooler operation or decreased resistance.