Definition
A point in an electrical circuit where unwanted resistance has developed at a junction, terminal, or splice, typically caused by corrosion, looseness, or contamination. The added resistance reduces current flow through the circuit and dissipates electrical energy as heat at the connection itself, often producing a hot spot that can damage wiring, melt insulation, or start a fire.
Plain English
A loose, dirty, or corroded electrical connection that doesn't conduct properly. It blocks some of the current and turns that lost energy into heat right at the bad joint.
Context Anchor
Seen during aircraft electrical troubleshooting, especially around battery cables, ground wires, switches, circuit breakers, lights, radios, and starter connections.
Derivation
Resistance comes from a Latin word meaning “to stand against.” In electricity, resistance is anything that stands against the flow of electricity. A high-resistance connection is a connection that stands against that flow more than it should.
Why Pilots Care
Can produce slow engine cranking, fluctuating instrument readings, intermittent radio failures, or localized overheating that risks fire.
Analogy
Think of a kinked garden hose. Water still flows, but less of it gets through, and pressure builds at the kink. In an electrical circuit, that 'kink' shows up as heat at the bad connection.
Grounding Statement
The key idea is that the circuit is not open, but the connection is poor enough to limit electrical flow.
Intuition Check
Do not assume “connected” means “good.” A high-resistance connection may be physically attached and still be electrically poor.
Example Sentence 1
The technician traced the dim landing light to a high-resistance connection at the corroded ground terminal on the firewall.
Example Sentence 2
A high-resistance connection in the main bus bar produced erratic attitude indicator behavior during the flight.