Buick LeSabre 1965 Service Manual page 673

ELECTRICAL SYSTEMS
DESCRIPTION 1 0 - 1 0 3
DRIVE PLATE &
SHAFT ASSEMBLY
DRIVE PAWL IN
PARK POSITION
IN RELAY SWITCH
SLOT
RELAY SWITCH ASSEMBLY
Figure 10-109—Wiper Mechanism in Park Position
the motor leads that extend be-
tween the motor and the gear box
are routed externally. The pump
is bolted to the bottom of the
wiper motor assembly and is
driven by the motor. The pump
is relay actuated by a switch on
the instrument panel.
To operate the Windshield washer,
the button on the switch must be
pushed in or forward. In so doing,
the wiper switch knob is mechani-
cally moved by the button to the
slow speed position. After the
washer has stopped, the knob
must be manually pulled back up
to the off position to stop the
wiper blades. The blades always
return to the depressed park po-
sition when the switch is moved
to off. If a faster wiper blade
speed is desired, the knob should
be pushed all the way down.
The single speed wiper switch has
no button. When the switch is
moved to the off position, the
blades do not return to a full
park position, but a few inches
away from the reveal molding.
See paragraph 10-56 for service
procedures on the single speed
windshield wiper.
All motors are held to the upper
cowl by three bolts. A water de-
flector is used on the motor shaft
and is located under the motor
drive crank and arm assembly.
Each wiper transmission is held
to the upper cowl by three
screws.
Although the transmission links
may appear to be the same they
are d i f f e r e n t , and right and
left t r a n s m i s s i o n s are not
interchangeable.
The drive link and bell crank as-
sembly which is located under the
air intake grille attaches to the
drive crank arm on the motor
shaft on one end. The right and
left housing and link assemblies
attach to the bell crank. The
linkage used with the overlap sys-
tem is different from that used
on the single speed wipers and
cannot be interchanged.
CAUTION: It is important that
when the wiper arms of the over-
lap system are in the park posi-
tion, the right arm must be
positioned below the left arm. If
the arms should be reversed the
system will not operate because
the left blade will lock into the
right blade assembly. The reason
for this is that the left wiper
transmission has a mechanical
advantage such that the speed of
the wiper blade on the left arm
is faster causing it to move away
from the park position more
rapidly. Should the blades become
bound up for reasons mentioned
above, the wiper should be turned
off immediately. The blades can
be freed only by removing the
wiper arms from the wiper trans-
mission or bending the blades to
free them.
b. Wiper Motor Operation
1. Wiper Off. In the off position,
the wiper gear drive pawl is lo-
cated in a slot in the relay switch
assembly. See Figure 10-109. In
this position it is pushing against
a spring loaded latch arm. The
latch arm, in turn, is pushing
against a flexible switch contact
which holds the switch contacts
open. Figure 10-109 shows the
wiper gear mechanism in the
"park" or "off" position.
2. Wiper On Low Speed. When the
owner turns the wiper on at the
dash switch, the circuit through
the relay switch assembly coil is
completed to ground at the dash
switch. The motor shunt field
ground connection at the dash
switch is maintained. See Figure
10-110. With the magnet coil
energized, the latch arm is at-
tracted to the magnet coil. This
action trips the latch arm away
from the flexible switch contact
which allows the switch contacts
to close. When the contacts close,