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[k.maslowski@comcast.net]

The Ford wiper control system on late model vehicles is completely different than anything you’re used to in the past. Examine the Ford wipers wiring diagram below. First, notice thathe wiper speed switch is now called a multi-function switch (MFS). It does not actually switch power to the wiper motor. It just acts a signaling device to tell the Smart Junction Box (SJB) what action you’d like it to take. In this case, the Smart Junction Box performs the same functions as a Body Control Module used in other makes and models. So you’ll have to check reference voltages coming into the MFS based on the position of the switch. Then you’ll have to check the grounds provided by the SJB the run to the control coils on the Park/Run and Hi/Low relays.

I have found a wiring diagram shows how Ford wipers work I'll copy and paste soon.

The SJB provides a reference voltage to the MFS. The voltage flows through resistors built into the MFS and then to ground. The SJB measure the voltage drop and based on the remaining voltage, determines what setting the driver has requested. The SJB then applies a ground to the appropriate relays which then provide power to the wiper motor and washer motor.