It sounds like an intermittent issue with the ignition switch. The ignition switch is the electrical component that the lock cylinder mounts to. It has several connectors and pins and over time due to wear and tear it can malfunction and can trigger this type of issues.
Since the Fiesta was not available in the USA in 2006, I am unable to provide the replacement instructions for the switch.
But the switch typically requires removal of the steering wheel.
Tuesday, November 9th, 2021 AT 9:03 PM