Table of Contents
Advertisement
•
INSTRUMENT PANEL AND GAUGES
8E - 7
ENGINE WARNING LAMP DIAGNOSIS
OIL PRESSURE FUNCTION
[
TURN
IGNITION
SWITCH " O N "
(DO NOT
TART ENGINE!
LAMP " O F F "
LAMP " O N "
DEFECTIVE
BULB
START AND IDLE
ENGINE
BULB SOCKET
OR WIRING
OPEN
LAMP STAYS
" O N "
TURN OFF
ENGINE
LAMP GOES
"Off"
CHECK FOR
GROUNDED
WIRING
DEFECTIVE
SWITCH
WARNING
LIGHT OK
CHECK FOR
LOW OIL
LEVEL
ENGINE OIL
PRESSURE
LOW
ENGINE OIL
PRESSURE
OK
TEST ENGINE
OIL PRESSURE
REFER TO
ENGINE SERVICE
DIAGNOSIS
DEFECTIVE
SWITCH
PR1448C
COMBINATION
OIL UNIT TEST (FIG. 4}
The combination o i l u n i t has 2 functions:
(1) The n o r m a l closed circuit keeps t h e o i l pressure
w a r n i n g l a m p on u n t i l there is o i l pressure.
(2) The sending provides a resistance t h a t varies
w i t h oil pressure.
To test t h e n o r m a l l y closed o i l l a m p switch, discon-
nect the l o c k i n g connector a n d measure t h e resis-
tance between t h e switch t e r m i n a l a n d t h e m e t a l
housing. T h e ohmmeter should read 0 ohms. S t a r t
the engine.
I f there i s o i l pressure, t h e ohmmeter should read
a n open circuit.
To test t h e sending u n i t , measure t h e resistance
between t h e sending u n i t t e r m i n a l a n d t h e m e t a l
housing. T h e ohmmeter should read open. S t a r t t h e
engine.
The ohmmeter should read between 30 to 55 ohms,
depending o n engine speed, o i l temperature, and o i l
viscosity.
I f the above results are n o t obtained, replace t h e
switch.
SENDING UNIT
(GAUGE)
SWITCH
(LIGHT)
898E-2
Fig. 4 Combination Oil Unit Terminals
SEAT BELT WARNING
SYSTEM
For t e s t i n g o f t h i s system refer to Section 8 M -
Seat B e l t W a r n i n g Systems.
BRAKE SYSTEM
WARNING LAMP (FIG. 5)
The b r a k e w a r n i n g l a m p i l l u m i n a t e s w h e n t h e
p a r k i n g brake is applied w i t h
t h e i g n i t i o n k e y
t u r n e d O N . T h e same l a m p w i l l also i l l u m i n a t e
should one o f t h e t w o service brake systems
f a i l
w h e n t h e brake pedal is applied. To test the system
t u r n t h e i g n i t i o n k e y O N , a n d apply t h e p a r k i n g
brake. I f t h e lamp fails t o l i g h t , inspect for a burned
out b u l b , disconnected socket, a broken or discon-
nected w i r e a t the switch. The l a m p also l i g h t s w h e n
the i g n i t i o n switch is t u r n e d t o the START position.
BRAKE
WARNING
LAMP
SWITCH
TO BRAKE
WARNING
LAMP
PR1451
Fig. 5 Brake Warning Lamp Switch
To test the service brake w a r n i n g system, raise the
vehicle o n a hoist and open a wheel cylinder bleeder
w h i l e a ^helper depresses t h e brake pedal a n d ob-
serves the w a r n i n g l a m p . I f the lamp fails t o l i g h t ,
inspect for a burned out b u l b , disconnected socket, a
Advertisement
Table of Contents
