Circuit Operation

Wiring Diagram:

Wiper Operation
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 a time interval between sweeps. The time interval is controlled by a solid-state timer in the wiper motor cover 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 end of sweep (inner wipe) position. the wiper motor reverses, and activates its external, depressed-park mechanism to lower the wipers to park position.

Pulse Operation
With the wiper switch in "DELAY" (pulse), battery voltage is applied to the wiper motor connector at terminal "3" through CKT 143. Voltage also is applied to terminal "D" through CKT 113 and terminal "F" through CKT 112.
For variable-pulse systems, the length of delay time between sweeps is controlled by the variable- pulse delay resistor. Delay is adjustable from 1 to 22 seconds. nominally. For fixed-pulse systems, the length of delay time between sweeps is non-adjustable.

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.
The circuit board supplies power to the wiper motor which runs continuously through the low-speed relay.

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 is also applied to 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 park 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 to "ON," battery voltage is applied to terminal "D" of the wiper motor assembly through CKT 113. The washer switch also applies voltage to the washer pump through CKT 228. The wiper motor has voltage applied through the low-speed relay and operates at low speed for 2 to 4 wipes.
When the washer switch is held on, the wiper motor circuit board will keep 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 park position after 2 to 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 park position. If the wiper switch is held in "MIST." the wipers will continue to operate until the switch is released. The circuit operation is the same as that of low speed.