Wiper Operation
When the wiper switch is in LOW, the following action occurs:
| • | Battery voltage applies to the park switch through CKT 96
and to the park switch contacts thorough CKT 91. |
| • | When the wiper switch is in LOW, the park switch closes its contacts,
which supplies battery voltage to the wiper motor through CKT 196 and
the wiper motor operates at low speed. |
When you move the wiper switch to the OFF position, the park switch
de-energizes, causing the mechanism to shift the wipers toward the depressed-park
position. When the mechanism is in the depressed-park position, the park switch
opens the wiper motor circuit, stopping the wipers.
With the wiper switch in HIGH, the following action occurs:
| • | Battery voltage applies directly to the wiper motor at terminal A
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 HIGH position because
of the voltage present at the low speed wiper motor brush when volage 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 assembly. |
A circuit breaker protects the wiper motor. The circuit breaker opens
if something blocks the wipers (such as ice on the windshield, for example).
The circuit breaker resets automatically after cooling.
Washer Operation
The washer pump is energized whenever you activate the washer switch
and runs as along as the switch is closed. Battery voltage is applied through
the washer switch and CKT 94 to the washer pump.
Activating the washer switch also moves the wiper switch to the LOW
position in order to start the wipers. The wipers must be turned off manually
after the wash cycle.
Mist Operation
When you move the wiper switch to MIST and then release the wiper switch,
the wipers make one sweep at low speed and return to the park position. The
circuit operation is the same as that of the LOW position.
Pulse System
In addition to the features of a standard (non-pulse) wiper system (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 cover assembly. The duration of the delay interval
is determined by the delay rheostat in the wiper/washer switch assembly.
A circuit breaker protects the wiper motor. If something blocks the
wipers (such as snow or ice, for example), the circuit breaker opens the circuit.
The circuit breaker resets automatically after cooling.
Wiper Operation
With the wiper switch in DELAY (pulse), the following action occurs:
| • | Battery voltage is applied to the wiper motor terminal B
of connector C1 through CKT 91. Voltage also is applied to terminal F
through CKT 94 and the pulse delay resistance in the wiper/washer switch
assembly. |
| • | 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, causing the wiper motor
to start. |
| • | A cam operates a contact in the wiper motor cover assembly, which
causes contact A to open when the wipers have completed sweeping. |
| • | Since the park switch coil remains energized, the wipers do not
park but remain just above the park position until contact A closes
again in order 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 LOW, battery voltage is applied at wiper
motor connector C1 terminals B and C through CKT 91 and
CKT 97. |
| • | The park switch coil energizes again and battery voltage is applied
to the park switch contacts and the wiper motor, which runs continuously. |
| • | With the wiper switch in the HIGH position, battery
voltage is applied directly to the wiper motor at terminal A without
passing through the park switch contacts. Terminal A is connected to
a separate wiper motor brush for high speed operation. |
| • | Voltage is also applied through the low speed wiper motor brush
to the park switch contacts and timer contact A to the park switch
coil. |
| • | The park switch coil remains energized in the HIGH position. |
| • | The current path from the low speed brush to the park switch
coil is completed through the wiper/washer switch assembly. An open in the
circuit causes the wipers to cycle in and out of the park position in HIGH
and possibly prevents low speed operation. |
Washer Operation
When you activate the washer switch, the following action occurs:
| • | Battery voltage is applied to the wiper motor cover assembly through
CKT 94 and CKT 97. |
| • | The battery voltage at terminal B of connector C1
energizes the park switch coil. |
| • | The cover assembly circuitry turns on the washer pump and wiper
motor by closing contacts A and B. |
| • | The cover assembly circuitry turns the wiper motor off approximately
6 seconds after it interrupts power to the washer pump. If the wipers
were in DELAY, LOW, or HIGH, the wipers return to that operation after the
wash cycle. |
Mist Operation
When you move the wiper switch to MIST and then release the switch,
the wipers make one sweep at low speed and return to the park position. The
circuit operation is the same as that of the LOW position.
