Buick LeSabre 1965 Service Manual page 675

ELECTRICAL SYSTEMS
TROUBLE SHOOTING AND TESTING 1 0 - 1 0 5
DRIVE AND LOCK PAWL GUIDE-
PINS IN GEAR POCKETS
DURING NORAAAL OPERATION
RELAY LATCH ARM IS HELD
OUT OF PATH OF GEAR BY
RELAY AAAGNET
Figure 10-111—Wiper Mechanism During Normal Operation
resulting cam action causes the
drive pawl to move into the relay
switch slot. See Figure 10-113.
As the drive pawl moves into the
switch slot it pushes against the
latch arm which, in turn, opens
the switch contacts. This action
opens the circuit to the wiper
motor and the wiper motor stops.
Refer to Figure 10-109 for wiper
gear mechanism in full park or
off position.
IMPORTANT: W i p e r s m u s t
operate in the low speed range to
shut off properly. Note that the
shunt field circuit is connected
to ground at the dash switch with
the dash s w i t c h in the off
position.
10-58 TROUBLE-SHOOTING
AND TESTING
Trouble-shooting and testing is
divided into two sections. The
first section covers testing with
the wiper motor in the car; the
second section covers testing with
the wiper motor out of the car.
a. Wiper in Car
1. Preliminary Inspection. Check
the following items:
(a) Body wiring properly con-
nected to wiper terminal board
and dash switch.
(b) Wiper to fire wall mounting
screw tight.
(c) D a s h s w i t c h s e c u r e l y
mounted.
(d) Fuse.
(e) With ignition switch turned on
there is a 12 volt supply at cen-
ter terminal of wiper terminal
board.
2. Checking W i p e r Operation.
Operate wiper independently of
the car wiring or dash switch,
as shown in Figure 10-114. Check
low and high speeds and if wiper
shuts off correctly.
(a) If wiper operates correctly,
see TROUBLE CHART - WIPER
IN CAR.
(b) If wiper still fails to operate
correctly, disconnect wiper link-
age from wiper motor and re-
check for proper wiper motor
operation.
(1) If wiper operates correctly
in Step (b), check linkage for
s e v e r e binding condition or
breakage.
(2) If wiper fails to operate cor-
rectly in Step (b), remove wiper
from car and check according to
instructions under subparagraph
b below.
b. Trouble Shooting—Wiper
Out of Car
1. Preliminary Test. Try oper-
ating wiper as shown in Figure
10-115. Check if wiper has low
speed, high speed, and shuts off
correctly.
2. Classify Trouble. If trouble is
found in Step 1, match trouble
with one of the troubles listed in
TROUBLE CHART - WIPER OUT
OF CAR. Note possible causes
listed, then turn to checking pro-
cedure for this trouble.
3. Procedure A
(Wiper Inoperative)
(a) Remove wiper gear box cover
or washer pump to gain access to
relay-switch assembly.
(b) Connect 12V power source to
wiper - hot side to center termi-
nal, ground side to gear housing.
See Figure 10-116. Do not con-
nect jumper to Terminal 1 and 3.
(c) To determine if wiper circuit
breaker is O.K., connect test light