Buick LeSabre 1965 Service Manual page 632

1 0 - 6 2 INDICATORS
ELECTRICAL SYSTEMS
ACCESSORY COMPARTMENT
MOUNTING BLOCK
RADIO SPEAKER
RADIO , - P R I N T E D CIRCUIT
HEADLAMP
SWITCH
PRINTED CIRCUI
DISCONNECT PLU
the clamped end of the left air
hose and puU out of the way to
gain access to the wiper switch.
c. Generator Charge Indicator
The red "GEN" warning light
should light when the ignition is
turned "ON" and before the en-
gine is started; if not lighted,
either the bulb is burned out or
the indicator light wiring has an
open circuit. After the engine is
started, the "GEN" light should
be out at all times; if the light
comes on, the generator belt may
be loose or missing, the generator
or regulator may be defective, or
the charging circuit may be de-
fective. See paragraph 10-18 for
trouble-shooting procedures.
To trace the generator indicator
light circuit, see Figure 10-65
Figure 10-64—Instrument Panel-Back Side
or 66. With the ignition switch
turned on (engine not running),
current flow is through the igni-
tion switch, out the "IGN" termi-
nal, through the generator light
in the instrument cluster, to the
"4" terminal of the regulator,
through the lower contacts of the
voltage regulator (held closed by
the spring), out the "F" termi-
nal of the generator, through the
brush and slip ring, through the
field, through another brush and
slip ring to ground.
Before the engine is started, the
generator light should glow at
about 1/2 brightness. This is
because the voltage in the circuit
before the light is about 12 volts,
but the voltage at the "4" ter-
minal after the light is about 5
volts. This makes the effective
voltage across the generator light
approximately 7 volts for about
1/2 brightness.
After the engine is started, the
voltage put-out by the generator
immediately closes the field re-
lay. This causes battery voltage
from the "3" terminal to be pre-
sent at the "4" terminal. See
Figure 10-65 or 66. Since battery
voltage is present on both sides of
the generator light, the light goes
out. If the generator light comes
with the e n g i n e running, the
charging circuit should be tested
at the first opportunity to deter-
mine the cause of the trouble.
See paragraph 10-21.
d. Oil Pressure Indicator
The engine oil pressure indicator
light is controlled by a pressure
operated switch located in the
main oil gallery at the right rear
of the engine.