Cadillac 60 Series 1963 Shop Manual page 329

12-48
ELECTRICAL SYSTEM
When the button is depressed, the switch lever is
mechanically moved to the low speed position.
The lever will stay in the low speed position until
the operator moves the lever to the "Off" position.
Electrical Wiper Operation
LOW SPEED - Moving the control switch lever
to the " L o " speed position, Fig. 12-70, connects
the relay control and shunt field circuit directly
to ground.
Battery current flows through the brown wire to
the wiper unit connector, terminal No. 2, and on
to the circuit breaker. From the circuit breaker,
current flows through the green wire to one con-
tact point on the relay switch. From this point,
current is directed not only through the relay coil
to the red wire to terminal No. 1, and thence
through the white wire to ground in the control
switch, but current also flows through the yellow
wire to the series and shunt fields of the motor.
The circuit divides here with some current
flowing through the series winding to the armature
and to ground, while the rest of the current flows
through the shunt field and black wire to terminal
No. 3. From this terminal, current flows through
the black wire directly to ground in the control
switch. The current bypasses the path of the 20
ohm resistor to ground because the resistance of
the control switch ground circuit is so much less.
MEDIUM SPEED - Moving the dash control
switch to the "Medium" position, Fig. 12-71,
connects a second resistor, located in the control
switch, in parallel with the resistor connected
from the shunt field circuit. These two resistors,
connected in parallel, allow less current to flow
in the shunt field resulting in medium speed.
HI SPEED - Moving the control lever to the
"Hi" speed position, Fig. 12-72, eliminates the
path to ground through the 13 ohm resistor in the
control switch, leaving only one resistor in the
shunt circuit. This one resistor allows even less
current to flow through the shunt field, which
results in high speed operation.
Mechanical Wiper Operation
When the switch lever is moved to any drive
position, the relay armature pulls the latch arm
out of contact with the drive pawl and the circuit
to the wiper motor is completed mechanically
through the relay control switch, Fig. 12-73. On
75 and commercial chassis unit see Fig. 12-74.
At this point, the motor turns the nylon gear and
the eccentric shaft. The drive plate is held from
rotating by the drive pawl contacting the stop arm.
After the nylon gear and eccentric shaft assem-
bly have rotated approximately 180°, the drive
pins of the drive and lock pawl assemblies slide
into their respective pockets in the nylon gear.
Wiper Unit
Connector
Relay And Switch
2
Shunt Field
Circuit Breaker
= Yellow
Green
Black
20
1 1 High Speed
Resistor
Washer Connector
X
Brown
Orange
Black
! I
Washer Relay Coil
White
Battery
Resistor
Off Lo Med. Hi
Fig. 12-70 Wiper Operation - Low Speed