Buick LeSabre 1965 Service Manual page 679

ELECTRICAL SYSTEMS TROUBLE SHOOTING 1 0 - 1 0 9
GEAR
ROTATION
DRIVE PAWL
ENGAGING
LATCH ARM
RELAY LATCH ARM
Figure 10-113—Wiper Mechanism During Parking Operation
NOTE: Cover exposed wire with
tape after the test.
(f) Disassemble motor section
and check the following:
(1) Hung brush.
(2) Solder connections at brush
holders.
(3) Splice joints at field coil con-
nections to leads.
(4) Open armature.
(5) Series field ground connection
on field lamina.
4. Procedure B (Wiper will not
shut off - Crank arm rotates
thru 360°)
(a) Observe if relay latch arm
spring is connected properly. See
Figure 10-117.
(b) Manually operate latch arm
to check it for possible binding
condition.
(c) If items in a and b check out,
connect power source to wiper
and connect jumper wire from
Terminal No. 3 to wiper housing,
Figure 10-117. Do not make any
connections from Terminal No. 1.
Manually actuate latch arm in di-
rection of arrow and observe if it
remains in energized position
(inside plastic switch housing out
of path of gear drive pawl). If it
remains in energized position,
check for grounded red leads
from coil to Terminal No. 1. If
red lead is not grounded, coil is
probably grounded internally and
relay switch should be replaced.
5. Procedure C (Wiper will not
shut off - Recycles)
NOTE: Crank arm oscillates in
a somewhat horizontal plane and
is accompanied by a loud "knock"
with each revolution of the gear.
(a) Check that drive pawl and
relay latch arm springs a r e
properly connected as shown in
Figure 10-117.
(b) Check wiper for low speed
operation. If wiper has high speed
only, check the following items:
(1) Solder joint at No. 3 wiper
terminal.
(2) Splice joint - black lead with
pink stripe to field coil leads.
(3) Splice
field coil.
joint - black lead to
(c) Check relay switch as follows:
(1) Remove small amount of in-
sulation from black lead with pink
stripe and connect test light be-
tween exposed wire and wiper
housing.
(2) Connect power source and
jumper to wiper as shown in Fig-
ure 10-117 and observe if test
light goes out once for each revo-
lution of gear or if light glows
steady. If light glows steady, re-
lay switch contacts are not open-
ing and switch is defective. If
light goes out each time drive
pawl moves into relay switch
slot relay switch is functioning
correctly.
6. Procedure D (Wiper has one
speed "slow")
(a) Check for grounded condition
in the internal black lead that
connects to wiper terminal No. 3.
R e f e r to Figure 10-117 for
Terminal No. 3 location.
(b) Disassemble motor section of
wiper and check for grounded
field coil.
IMPORTANT: Occasionally t h e
field coils are loose on the poles
and this enables them to slide