In addition to the features of a conventional (non-pulse) wiper system (mist, low and high speeds), the pulse-type windshield wiper/washer system includes an operating mode in which the wipers make single sweeps with an adjustable time interval between sweeps. The time interval is controlled by a solid-state timer in the wiper motor assembly. The duration of the delay interval is determined by the delay resistor in the wiper/washer switch assembly.

When the wiper switch is turned off, the wiper motor returns the wipers to the end of the sweep (innerwipe) position and then reverses, activating its external depressed-park mechanism to lower the wipers to the park position.

Pulse Operation

With the wiper switch in DELAY (pulse), battery voltage is applied to the wiper motor at terminal B through CKT 143. Voltage also is applied to terminal D through CKT 113 and terminal E through CKT 112.

The length of delay time between sweeps is controlled by the variable-pulse delay resistor. The delay is adjustable from 1-22 seconds.

Low-Speed Operation

In the LO position of the wiper switch, battery voltage is applied to the wiper motor connector at terminal B through CKT 143, terminal E through CKT 112, and terminal D through CKT 113.

High-Speed Operation

In the HI position of the wiper switch, battery voltage is applied at terminal B, C, and E of the wiper motor assembly through CKTs 143, 92, and 112. Voltage also is applied at terminal D through CKT 113.

Park Position Operation

When turned OFF from any position, the wipers complete the last sweep and park. When the wiper switch is in OFF, the wiper motor assembly has battery voltage applied to terminal B only, from CKT 143. When the end-of-sweep switch opens, the control circuit reverses the wiper motor which activates the external depressed-park mechanism. The wiper motor continues to run until the park switch opens.

Washer Operation

When the washer switch is turned ON, battery voltage is applied to terminal D of the wiper motor assembly through CKT 113. The washer switch also applies voltage to terminal A which turns on the washer pump through CKTs 94 and 228. The wiper motor has voltage applied through the low-speed relay and operates at low speed for 2-4 wipes after the washer switch is released.

When the washer switch is held in the ON position, the wiper motor circuitry keeps the washer pump on only as long as the washer switch is held ON.

If the wipers had been in DELAY, LO, or HI, they would return to that operation after the wash cycle. If in OFF, they then return to the park position after 2-4 wipes.

Mist Operation

When the wiper switch is moved to MIST and released, the wipers make one sweep at low speed and return to the park position. If the wiper switch is held in MIST, the wipers continue to operate until the switch is released. The circuit operation is the same as that of LO.