Wiper and Washer Systems: Description and Operation

WIPER OPERATION
The wiper switch is controlled by a lever built into the combination switch.
There are three wiper switch positions:
- LO speed
- HI speed
- INT (Intermittent).

With the ignition switch in the ACC or ON position, power is supplied:
- through 20 A fuse [No. 19, located in the fuse block (J/B)]
- to wiper motor terminal (B) and
- to wiper amplifier terminal (5).
Ground is supplied to wiper amplifier terminal (3) through body grounds (M2) and (M61).

Low and high speed wiper operation
Ground is supplied to wiper switch terminal (17) through body grounds (E10) and (E34).
When the wiper switch is placed in the LO position, ground is supplied:
- through terminal (14) of the wiper switch
- to wiper motor terminal (L).
With power and ground supplied, the wiper motor operates at low speed.

When the wiper switch is placed in the HI position, ground is supplied:
- through terminal (16) of the wiper switch
- to wiper motor terminal (H).
With power and ground supplied, the wiper motor operates at high speed.

Auto stop operation
With wiper switch turned OFF, wiper motor will continue to operate until wiper arms reach windshield base.
When wiper arms are not located at base of windshield with wiper switch OFF, ground is supplied:
- from terminal (14) of the wiper switch
- to wiper motor terminal (L), in order to continue wiper motor operation at low speed.

Ground is also supplied:
- through terminal (13) of the wiper switch
- to wiper amplifier terminal (2)
- through terminal (7) of the wiper amplifier
- to wiper motor terminal (P)
- through terminal (E) of the wiper motor, and
- through body grounds (M2) and (M61).
When wiper arms reach base of windshield, wiper motor terminals (P) and (B) are connected instead of terminals (P) and (E). Wiper motor will then stop wiper arms at the PARK position.

Intermittent operation
The wiper motor operates the wiper arms one time at low speed at a set interval of approximately 3 to 13 seconds. This feature is controlled by the wiper amplifier.
When the wiper switch is placed in the INT position, ground is supplied:
- to wiper amplifier terminal (1)
- from wiper switch terminal (15)
- through body grounds (E10) and (E34)
- to wiper motor terminal (L)
- through the wiper switch terminal (14)
- to wiper switch terminal (13)
- through wiper amplifier terminal (2)
- to wiper amplifier terminal (3)
- through body grounds (M2) and (M61).

The desired interval time is input:
- to wiper amplifier terminal (8)
- from wiper switch terminal (19)
- to wiper switch terminal (20)
- through body grounds (E10) and (E34).
The wiper motor operates at low speed at the desired time interval.

WASHER OPERATION
With the ignition switch in the ACC or ON position, power is supplied:
- through 20 A fuse [No. (19), located in the fuse block (J/B)]
- to washer motor terminal (2).

When the lever is pulled to the WASH position, ground is supplied:
- to washer motor terminal (1), and
- to wiper amplifier terminal (6)
- from terminal (18) of the wiper switch
- through terminal (17) of the wiper switch, and
- through body grounds (E10) and (E34).
With power and ground supplied, the washer motor operates.
When the lever is pulled to the WASH position for one second or more, the wiper motor operates at low speed for approximately 3 seconds to clean windshield. This feature is controlled by the wiper amplifier in the same manner as the intermittent operation.