Cadillac 60 Series 1963 Shop Manual page 339

12-58
ELECTRICAL SYSTEM
5. If circuit to relay coil checks out, leave 12
volt supply connected as explained in step 4a
above and connect a jumper wire from terminal
No. 1 to housing. Failure of relay armature to
pull in indicates a weak or open relay coil.
6. If steps 4 and 5 check out correctly, test
relay switch as follows:
a. Leave battery and jumper wire connected as
described in steps 4 and 5 and check for 12 volts
of switch terminal to which yellow lead attaches.
If relay pulls in properly but no voltage reading
is obtained, a defective switch is indicated.
b. Disconnect jumper wire from terminal No. 1
and check that relay armature moves away from
coil pole. If wiper gear mechanism is in full
park position, disconnect large coil spring be-
tween drive and lock pawls. Check for 12 volts
at switch terminal to which yellow lead attaches.
No voltage reading indicates a defective relay
switch.
c. Leave voltmeter connected as in Step b and
manually push switch stop tab toward relay coil.
If voltage reading is still obtained, a defective
switch is indicated.
b. Motor Checks
For motor checks, disassemble motor but leave
field assembly in housing.
1. Check armature for following circuit condi-
tions:
a. Use growler to test for either open or short
circuit.
b. Use test lamp to check for grounded circuit.
2. Inspect case and brush assembly for worn
brushes, brushes binding in holders, defective
brush springs, loose solder joints, and dirty or
defective circuit breaker contacts.
3. Check field assembly for following circuit
conditions:
a. Disconnect yellow lead from relay control
switch and connect test lamp between yellow lead
and brush holder to which internal, field lead is
attached. If lamp does not light, an open series
field is indicated.
b. With yellow lead disconnected, connect test
lamp between yellow lead and terminal to which
black motor lead attaches. If lamp does not light,
an open shunt field is indicated.
c. With yellow lead disconnected, connect test
lamp between yellow lead and field laminations.
Be sure steel case and brass ground strap are
not touching housing. If lamp lights, one of the
fields is grounded.
c. Operating Wiper on Bench
After assembling unit, check motor operation in
the following manner. Be sure brass ground strap
is connected to wiper housing.
a. " L o " speed-Connect 12 volt supply to center
(No. 2) terminal and ground housing. Connect
jumper wire from No. 1 and No. 3 terminals to
ground.
b. " H i " speed-Remove jumper from No. 3
terminal.
c. "Off"-Remove jumper from No. 1 terminal
and reconnect jumper from No. 3 terminal to
ground.
WINDSHIELD WIPER AND WASHER DIAGNOSIS CHART
CONDITION
Wiper Inoperative.
CAUSE
No power supply at wiper.
Defective dash switch.
Wiper unit latching mechanism
binding.
Defective relay control.
Defective wiper motor.
Drive shaft seized in eccentric
gear shaft.
REMEDY
Check circuit and body wiring
as described in Note 79a.
Check dash switch mounting as
described in Note 79b.
Check wiper latching mecha-
nism as described in Note 80a.
Check relay control as de-
scribed in Note 80a.
Check motor a s described in
Note 80b. Replace if neces-
sary.
Free up shaft or replace parts.