* Increased Resistance: A corroded or loose ground wire creates increased electrical resistance. This resistance generates heat. If the resistance is high enough and the current flow significant, this heat can ignite nearby flammable materials (insulation, wiring harnesses, etc.).
* Arcing: A poor connection in a ground wire can cause arcing – a spark that jumps across the gap. Arcing produces intense heat, which is a significant fire hazard.
* Overloading other circuits: A faulty ground can force current to flow through unintended pathways, overloading other wires and components, potentially causing them to overheat and fail, leading to a fire.
* Short Circuit: In some cases, a completely broken ground wire can lead to a short circuit, which is a major cause of electrical fires.
It's important to understand that a ground wire doesn't typically *initiate* the fire; it allows or exacerbates the conditions for one to occur. The underlying cause might be a malfunctioning electrical component, but a bad ground can be the crucial factor enabling the fire to start and spread.
