Chrysler RAM TRUCK 2500 1994 Service Manual page 261

7 - 6 COOLING SYSTEM •
COOLING SYSTEM DIAGNOSIS (ALL EXCEPT DIESEL)
S T A N D A R D G A U G E
(TYPICAL)
O P T I O N A L G A U G E
(TYPICAL)
H I G H
TEMP.
L O W
TEMP.
H I G H
TEMP.
C O N D I T I O N A N D C N E C K S D I A G N O S I S
GAUGE
R E A D I N G L O W :
(1) Verify gauge reading. Is a low temperature indicated?
(2) Is code 17 recorded in On-Board Diagnostics memory?
(3) Is the gauge reading in the cold range?
(4) Low coolant level during cold ambient temperatures
(accompanied with poor heater performance).
(5) Coolant level is correct.
N o r m a l G o u g e T r a v e l
(1) Inspect temperature gauge sending unit. Refer to Group 8,
Electrical. Repair or replace sending unit as necessary.
(2) If code 17 is recorded, replace the thermostat. If not, the
thermostat is not the cause of the low gauge reading.
(3) Inspect for disconnected sending unit electrical connector
or incorrect sending unit. Ensure that gauge sending unit
is installed and not an indicator light switch.
(4) WARNINGS DO NOT REMOWE THE RADIATOR
CAP OP A HOT
#
PRESSURIZED E N G I N E .
SERIOUS INJURY C A N RESULT FROM
SCALDING COOLANT®
Inspect coolant level in the coolant reserve tank and
radiator. Inspect system for leaks.
(5) Inspect heater door controls. Refer to Group 24, Heating
and Air Conditioning.
G A U G E R E A D I N G H I G H . ( N O P R E S S U R E B L O W O F F
FROM RADIATOR P R E S S U R E CAP OR STEAM FROM
C O O L A N T R E S E R V E / O V E R F L O W T A N K ) :
(1) Verify gauge reading. Is a high temperature reading
indicated?
(2) Gauge reading high without signs of boiling.
(3) Low coolant level in radiator and coolant reserve tank.
(4) Coolant level in radiator is low, but not low in coolant
reserve tank.
H i g h G a u g e R e a d i n g — H o t W e a t h e r — H e a v y L o a d
(1) Compare gauge reading to High Gauge Reading
illustration above.
(2) Inspect for grounded gauge, sending unit or circuit.
Refer to Group 8, Electrical.
(3) a - F i l l to full.
b —Inspect for leaks in system and repair as necessary,
c — Ensure radiator pressure cap was shut tight. Verify
proper operation of the radiator cap upper and
lower seals.
(4) o —Fill to full.
b — Inspect for leaks in the system and repair as necessary,
c — Inspect for leaks in the coolant reserve tank to
radiator hose,
d — Verify proper operation of the radiator cap upper
and lower seals.
J9407-3