Buick LeSabre 1965 Service Manual page 852

ACCESSORIES
GUIDE-MATIC POWER HEADLAMP CONTROL 1 1 - 1 1 9
If customer complains of the
Guide-Matic dimming too late or
too soon, go to "Sensitivity
Adjustment".
2. Preparation
NOTE: If car has been in the
sun immediately prior to check-
ing, allow to cool in a covered
place for approximately one hour
before the checks are made.
(a) Turn on headlamps.
(b) Allow minimum of one minute
warmup.
(c) Follow tests progressively
under the specific complaint until
trouble is located.
3. Headlamps Stay On
Low Beam:
(a) Remove the phototube unit
harness from the amplifier unit
and operate the foot switch.
(1) If headlamps are on low beam
in both positions of the foot
switch, go to Step b.
(2) If headlamps are on upper
beam in one position of foot
switch, trouble is in the photo-
tube unit. Remove both units for
servicing.
b. Remove the 4 amp fuse from
the fuse holder near the amplifier
unit and ratchet the foot switch.
(1) If the headlamps c h a n g e
beams, the amplifier unit is faulty
and s h o u l d be removed for
servicing.
(2) If u p p e r beam is not ob-
tained, trouble is in power relay,
foot switch, or car harness.
4. Headlamps Stay On
Upper Beam:
(a) Ground the white wire of the
phototube harness. (It may be
necessary to lower amplifier. If
so, use external ground for case
of amplifier.)
(1) If headlamps remain on upper
beam, go to Step b.
(2) If headlamps go to lower
beam, trouble is in the phototube
unit. Remove amplifier and photo-
tube unit for servicing.
(b) Remove red wire from foot
switch -
(1) If headlamps go to low beam,
replace foot switch.
(2) If headlamps remain on upper
beam, check power relay and if
okay, r e m o v e amplifier for
servicing.
5. No Overriding High Beam
(a) Check to see if red wire is
connected to foot switch. If not,
make correction.
(b) If it is, remove red wire and
place a jumper from the red wire
to ground. If override is obtained,
replace foot switch.
SPRING
KNOB-SENSITIVITY CONTROL
VERTICAL ADJUSTING SCREW
BASE
SCREW
BASE
NUT
PIN
45000, 46000 AND 48000 SERIES
WIRING HARNESS TO AMPLIFIER
49000 SERIES
SCREW
WIRING HARNESS
DIMMER FOOT SWITCH
Figure 11-165— Photo tube and Dimmer Switch Installation