What relay is connected to the windshield wipers on a 2000 Ford Windstar?

The 2000 Ford Windstar uses a body control module (BCM) rather than a dedicated relay for the windshield wipers. The BCM controls the wiper motor based on signals from the wiper switch. There isn't a single relay you can replace to fix wiper problems; the issue is usually within the BCM, the wiper motor itself, the switch, or the wiring between them.