Rolls-Royce Silver Shadow - Windscreen Wipers, Motors and Washers Fault Diagnosis

Rolls-Royce Silver Shadow & Bentley T Series
Workshop Manual
Windscreen Wipers, Motors and Washers Fault Diagnosis (Refer to Figs. M80 - 84)
Symptom
Wipers fail to operate
on NORMAL or FAST speed.
INTERMITTENT
satisfactory.
Wipers fail to operate on any
switch setting.
FAST speed inoperative
NORMAL wipe,
washl'wipe
cycle and intermittent cycle
satisfactory.
INTERMITTENT wipe cycle
inoperative, normal wipe and
washiwipe satisfactory.
INTERMITTENT wipe cycle
runs continuously. Normal
wipe and
washiwipe
satisfactory.
INTERMITTENT wipe cycle
operates one cycle only.
Wash cycle satisfactory but
wipe cycle inoperative.
Normal and Fast speed
wipers inoperative.
Possible Cause
No supply voltage at wiper
switch.
Wiper switch faulty.
Supply faulty.
Number
2 fuse ' blown'.
Wiper motor faulty.
Faulty earth connection.
Wiper switch faulty.
Faulty cable connection.
Intermittent wipe unit faulty
Faulty wiper switch.
Faulty intermittent wipe unit.
Intermittent wipe unit faulty.
Washr'wipe control unit faulty.
Action
Chapter M
Check supply from fuse 2 to terminal 8 of
wiper switch.
With wiper switch on FAST or NORMAL,
check for live feed at switch terminal 10.
Operate
washl'wipe switch, if washer fails
to operate check supply at
wash/wipe unit
and fuse
2.
Replace fuse.
Disconnect the motor socket and test the
motor. Check motor brushes.
Check soundness of earth connections at
right-hand
' A' post upper earth point,
connection
2 of wash/wipe control box and
14B cable at wiper switch.
Switch to FAST speed and check for live
feed at terminal
5.
Check continuity of 14YG cable at motor
socket, motor condenser,
toeboard socket
and wiper switch.
Remove auxiliary swith plug from motor and
check for continuity between terminals
1 and
3 on the intermittent wipe unit. Allow 7
seconds delay for circuit to charge.
At the wiper switch, check for continuity
between connections
3 and 4, 12 and 13,
1 and 7 (see previous note).
Verify that terminals
1 and 3 on the
intermittent wipe unit are not made
continuous1
y.
Replace unit.
Switch to intermittent wipe cycle, if
intermittent wipe
operates,the wash/wipe
unii is faulty.