Warning Lamp System Tests; Low Oil Pressure Warning Lamp Circuit Test; Combination Oil Switch And Connection - Dodge D150 1990 Service Manual

8E - 6 INSTRUMENT PANEL AND GAUGES •
(b) W i r i n g a n d connections between m u l t i p l e
connector and p r i n t e d c i r c u i t board t e r m i n a l s .
(c) C i r c u i t c o n t i n u i t y between p r i n t e d circuit
board t e r m i n a l s and gauge t e r m i n a l s .
I f these items check okay, fuel gauge i s defec-
t i v e and m u s t be replaced.
(2) I f the fuel gauge meets specifications check fuel
t a n k a n d o r i g i n a l i n s t a l l e d fuel t a n k sending u n i t as
follows:
(a) Carefully remove fuel t a n k sending u n i t
f r o m t a n k . Connect sending u n i t w i r e a n d j u m p e r
w i r e as described i n t h e procedure.
(3) I f fuel gauge n o w checks w i t h i n specifications,
o r i g i n a l l y installed sending u n i t is electrically okay,
check following as possible cause:
(a) Ground strap f r o m sending u n i t t o fuel l i n e
for c o n t i n u i t y .
(b) Sending u n i t deformed. M a k e sure sending
u n i t float a r m moves freely, p i c k u p tube is n o t
bent upwards so t h a t there is n o t a n interference
f i t w i t h bottom of t a n k and inspect float.
(c) Sending u n i t i m p r o p e r l y installed. I n s t a l l
properly.
(d) M o u n t i n g flange o n fuel t a n k for sending
u n i t deformed. Feel for interference f i t o f sending
u n i t t o bottom of t a n k . I t is permissible t o bend
p i c k u p tube down a l i t t l e near m o u n t i n g flange to
g a i n interference f i t .
(e) F u e l t a n k b o t t o m deformed causing i m -
proper positioning o f sending u n i t pick up tube. Re-
place or repair t a n k a n d recheck sending u n i t .
Refer t o F u e l T a n k Section o f Group 14 - F u e l Sys-
t e m .
WARNING LAMP SYSTEM TESTS
LOW OIL PRESSURE WARNING LAMP
CIRCUIT TEST
The l o w o i l pressure w a r n i n g l a m p w i l l i l l u m i n a t e
w h e n t h e i g n i t i o n k e y i s t u r n e d to t h e O N position.
The l a m p also i l l u m i n a t e s i f the engine o i l pressure
drops below a safe o i l pressure level.
To test the system t u r n i g n i t i o n k e y t o t h e O N po-
sition.
I f t h e l a m p f a i l s t o l i g h t , inspect for a b r o k e n or
disconnected w i r e a t t h e o i l pressure combination
u n i t , w h i c h i s located a t t h e rear o f t h e engine ( F i g .
3) . I f the w i r e a t the connector checks good, p u l l con-
nector loose from t h e s w i t c h a n d w i t h a j u m p e r w i r e
ground the l i g h t s w i t c h t e r m i n a l t o t h e engine ( F i g .
4) . W i t h t h e i g n i t i o n k e y t u r n e d t o t h e O N position
check t h e w a r n i n g l a m p . I f l a m p s t i l l fails t o l i g h t ,
inspect for a burned out b u l b or disconnected socket
i n the cluster.
I f l i g h t c o m e s o n , proceed a n d s t a r t engine. I f t h e
l a m p remains on, i m m e d i a t e l y t u r n engine o f f a n d
check engine o i l pressure according t o procedures as
o u t l i n e d i n Group 9 - E n g i n e o f t h i s m a n u a l . I f i t i s
determined t h a t o i l pressure is according t o specifica-
tions, check for a grounded w i r e and/or replace t h e
o i l pressure sending u n i t (refer t o combination o i l
u n i t test).
Fig. 3 Combination Oil Switch and Connection