Buick LeSabre 1965 Service Manual page 851

1 1 - 1 1 8 GUIDE-MATIC POWER HEADLAMP CONTROL ACCESSORIES
phototube unit into a signal strong
enough to actuate the power relay.
It is mounted on the lower edge
of the dash under the glove box.
See Figures 11-163 and 11-164.
The power relay has special
heavy duty contacts for switching
headlamp beams. It is located
on the left side of the steering
column brace on 49000 Series
(see Figure 11-164) and on the
accessory mounting b l o c k on
45000, 46000 and 48000 Series
(see Figure 11-163).
The dimmer-override foot switch
provides automatic control of the
headlamp beams in one position,
and manual low beams in the
other position. In automatic po-
sition, a spring loaded momentary
contact type switch is also pro-
vided. Depressing the foot switch
slightly provides an overriding
upper beam condition regardless
of light on the phototube unit.
This permits the driver to signal
if an approaching vehicle fails to
switch to low beam, and also, in
a lighted area provides a simple
test for automatic position of the
foot switch.
The Guide-Matic is connected to
turn on with the headlamps. After
approximately 30 seconds warm-
up period, the Guide-Matic will
p r o v i d e complete a u t o m a t i c
switching of the headlamp beams.
Street lights and other extraneous
lights encountered in the city are
sufficient to maintain its vehi-
cle headlamps on low b e a m .
Occasionally, when trailing an
older model car with poor light-
ing on the rear, or due to some
other unfavorable condition, it
may be desirable to change the
foot switch position to manual
low beam. The Guide-Matic is
disconnected from i t s vehicle
headlamps in this position, but
is not turned off. It continues to
function as long as vehicle head-
lamps are turned on.
b. Trouble Shooting:
1. Determination of Complaint -
Turn Guide-Matic on and allow
at least one minute warmup.
In a lighted area, the headlamps
should be on low beam in both
positions of the foot switch. If
not, go to "Headlamps Stay On
Upper Beam."
With black cloth over the photo-
tube unit, the headlamps should
be on upper beam in one position
of the foot switch. If not, go to
"Headlamps Stay On Lower
Beam".
With the black cloth removed from
the phototube unit, in one position
of the foot switch, upper beam
should be obtained by depressing
the foot switch 1/4 inch. If not,
go to "No Overriding Upper
Beam".
PHOTOTUBE
HARNESS
TAPE
AMPLIFIER
FOOT SWITCH
Figure 11-164—Guide-Matic Installation - 49000 Series