Mercury Grand Marquis windshield wipers malfunctioning and won't shut off on Mercury Grand Marquis

Some Mercury Grand Marquis owners report experiencing issues with malfunctioning windshield wipers that won't shut off, often due to a variety of potential causes. A common concern is a faulty wiper switch, which may require replacement to restore control over the wipers. Additionally, problems with the wiper motor can prevent it from responding to switch commands, causing the wipers to remain active. In some cases, unplugging the multifunction switch can stop the wipers, indicating that this component may need to be replaced. Grounding issues can also lead to the wipers not shutting off, necessitating attention to the motor's grounding connections. Furthermore, a broken park plate mechanism inside the wiper motor can prevent the wipers from parking correctly when turned off. To effectively resolve these issues, it is recommended that owners systematically diagnose the problem, and if uncertainties arise, consulting a professional mechanic for a thorough inspection and repair is advisable.