Ford 1998 Windstar Owner's Manual page 85

Controls and Features
Rear Wiper and Washer (If equipped)
The controls for the rear wiper and washer can be found on the
instrument panel to the right of the instrument cluster below the
climate control system. The rear wiper and washer controls
operate with the ignition in the ACC or ON positions.
The rear wiper switches
To operate the rear wiper, press the rear wiper switch. If the
front wipers are off, on intermittent or low speed operation, the
rear wiper will have an intermittent operation. If the front
wipers are in high speed operation, the rear wiper will
continuously operate.
The rear wiper will also perform one wipe of the rear window
when the front wipers are in intermittent or low speed
operation and the transaxle is shifted into R (Reverse). If the
front wipers are in high speed operation and the transaxle is
shifted into R (Reverse), the rear wiper will continuously
operate.
Do not activate the washer for longer than fifteen seconds
continuously. This could damage the washer pump system.
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