Table of Contents
Advertisement
8-50
1977 PONTIAC SERVICE MANUAL
I
COUllTESy LAMP
STEERING COLUMN
I
H
\
A / C DUCT
/
I
1'
A D
A C C E L ~ R A T O R
FUSE BLOCK
LINKAGE
BRAKE PEDAL
31 84
I
Fig. 8-76 "Hush"Panel, Early B Series, LH
INSTRUMENTS
GENERAL DESCRIPTION
Instruments consist of fuel gage, temperature indicator
lamp, generator lamp, oil pressure indicator lamp, and
speedometer. See Section 9 for optional Rally Gages. Service
on instruments can be obtained through authorized branches.
However, knowledge of instrument circuit checks will help
in determining if operating dificulties lie in instrument itself
or its allied circuit.
Instruments have been designed for easy removal by
elimination of separate ground straps. With the grounding
provisions intergrated with the instrument panel wiring, the
instruments can be removed after removing a separate trim
plate (except X Series).
FUEL GAGE
An electrical fuel gage is used on all series, consisting
of an instrument panel gage and a fuel tank pick-up. The fuel
gage indicates the quantity of fuel in tank only when ignition
switch is turned to "on"or "accessory"positions.
When ignition is turned to "off'or "start"positions, the
pointer may come to rest at any position. The letters "E"and
"Pan fuel gage are used to point out direction of indicator
travel only.
Gage readings are made from five markings on gage face.
The left-hand line indicates empty, the centerline half-full and
the right line full.
TEMPERATURE INDICATOR LAMP
The engine temperature indicator lamp is controlled by
a thermal switch which senses engine coolant temperatures.
When the ignition switch is turned to "start"position,
a test circuit is closed to indicate whether the red lamp is
functioning properly.
NOTE: In H and HM Series, temperature and oil
pressure lamps are combined. Operation of this system
is covered in Section 6C, Carburetion and Fuel Systems,
and the wiring diagram is shown in Fig. 8-76A.
If the cooling system does not hold pressure due to
pressure cap being left loose, or accident such as puncture of
radiator, rupture or disconnection of a hose, or use of low
boiling point anti-freeze, the calibration temperature of red
lamp heat indicator may not be reached, in spite of boiling.
NOTE: Low boiling coolants such as water will not
operate lamp.
GENERATOR LAMP
The red generator indicator lamp, located in the
instrument cluster, should light when the ignition switch is
turned on and engine is not running. If not, either the bulb
is burned out or generator has an open circuit.
When the generator voltage output becomes greater than
the battery voltage, the red lamp should go out. This does
not, however, indicate whether the battery is being charged
or regulator is functioning properly.
The charging system should be checked if trouble is
experienced. See Engine Electrical Section, 6D, of the
manual.
ENGINE OIL PRESSURE INDICATOR
LAMP
The engine oil pressure indicator lamp is controlled by
a pressure-operated switch located on the oil filter support,
or on the side of the block. When engine is running, the lamp
operates only when oil pressure is not satisfactory. This lamp
should come on when ignition is turned ON and engine is not
running.
The oil pressure switch breaks contact at 4
*
2
psi on
increasing pressure and makes contact at 4
*
2
psi on
decreasing pressure (except V6, which is 3
*
2
psi).
H and
HM
Series use an electric fuel pump with 140 L-4
and 231 V-6 engines. Power for the pump is fed through the
oil pressure switch, and the pump will not operate unless
suficient pressure is present at the oil pressure switch. For
further information on this system, see Section 6C, and Fig.
8-76A.
Advertisement
Table of Contents
