With the wiper switch in DELAY (pulse), battery voltage is applied to the wiper motor at terminal B of connector C1 through the GRY wire. Voltage is also applied to terminal F through the PNK wire and the pulse delay resistor in the wiper/washer switch. The battery voltage at terminal B energizes the park switch coil, which closes its contacts. In response to the voltage at terminal F, the solid-state timer momentarily closes contact A, which applies battery voltage at terminal B to the contacts of the park switch to start the wiper motor.

A mechanical arm (end of sweep input) operates contacts in the wiper motor cover, which causes contact A to open when the wipers have completed their sweep. Since the park switch coil remains energized, the wipers do not park, but remain just above the park position until the cover circuitry closes contact A again to start another sweep.

The length of delay time between sweeps is controlled by the variable pulse delay resistor. The delay is adjustable from 0-25 seconds.

With the wiper switch in LO, battery voltage is applied at the wiper motor connector C1, terminals B and C through the GRY and DK GRN wires. The park switch coil is again energized and battery voltage is applied to the park switch contacts and the wiper motor, which runs continuously.

With the wiper switch in the HI position, battery voltage is applied directly to terminal A of the wiper motor without passing through the park switch contacts. Terminal A is connected to a separate wiper motor brush for high-speed operation. The park switch coil remains energized in the HI position because of the voltage present at the low-speed wiper motor brush when voltage is applied to the high-speed brush. The current path from the low-speed brush to the park switch coil is completed through the wiper/washer switch. An open circuit condition in this circuit will cause the wipers to cycle in and out of the park position in HI and possibly prevent low-speed operation.

When turned off from HI, the wipers complete the last sweep at low speed and park. To do this, the wiper motor receives voltage in the OFF position of the wiper switch, which is applied through the DK GRN wire to terminal C of connector C1. The park switch is de-energized when the wiper switch is moved to OFF, the contacts remain closed until the wipers reach park position.

When the washer switch is pushed, battery voltage is applied to the circuit board through the PNK and GRY wires. The park switch coil is energized by the battery voltage at terminal B of connector C1. The circuit board turns on the washer pump and the wiper motor by closing contacts A and B. The circuit board turns the wiper motor off approximately 6 seconds after it interrupts power to the washer pump. If the wipers had been in DELAY, LO, or HI, they would return to that operation after the wash cycle.

When the wiper switch is turned to MIST and released, the wipers make one sweep at low speed and return to park. The circuit operation is the same as that of LO.