Wiper and Washer Systems: Description and Operation

FRONT WIPER AND WASHER

System Description

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 (with intermittent operation)

With the ignition switch in the ON or START position, power is supplied:
- through 20 A fuse [No. 25, located in the fuse block (J/B)]
- to wiper motor terminal B, and
- to front wiper switch terminal 15 (with intermittent operation).

Low and High Speed Wiper Operation
Ground is supplied to wiper switch terminal 17 through body grounds E7 and E37.
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 the wiper switch turned OFF, the 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 provided:
- 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 motor terminal P
- through terminal E of the wiper motor, and
- through body grounds E7 and E37.

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 STOP 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 (INT SW) combined with wiper switch. When the wiper switch is placed in the INT position, ground is supplied to wiper amplifier.

The desired interval time is input to wiper amplifier (INT VR) from wiper volume switch combined with wiper switch.

Then intermittent ground is supplied:
- to wiper motor terminal L
- from terminal 14 of wiper switch
- through wiper amplifier (OUTPUT).
The wiper motor operates at low speed at the desired interval.

WASHER OPERATION
With the ignition switch in the ON or START position, power is supplied:
- through 20 A fuse [No. 25, located in the fuse block (J/B)]
- to front washer motor terminal +.

When the lever is pulled to the WASH position, ground is supplied:
- to front washer motor terminal -
- from terminal 18 of the wiper switch
- through terminal 17 of the wiper switch, and
- through body grounds E7 and E37.
With power and ground supplied, the washer motor operates.

Without intermittent operation, the wiper motor operates while the lever is pulled to the WASH position. With intermittent operation, 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 intermittent operation.