TM 5-2420-231-23-1
0021
Table 1. Engine Coolant Temperature Gauge Indicates High Temperature,
Does Not Function, or Is Inaccurate - Continued.
021
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Engine Coolant Temperature 22. Verify coolant temperature gauge
Coolant Temperature Gauge
Gauge Indicates High
is between lowest and highest
Between Lowest and Highest Marks
Temperature, Does Not
marks (TM 5-2420-231-10).
- Proceed to step 23.
Function, or Is Inaccurate -
Coolant Temperature Gauge Above
Continued
Highest Mark at All Times - Proceed
to Test Step 7.
Coolant Temperature Gauge Below
Lowest Mark at All Times - Proceed to
Test Step 8.
23. Start and operate engine (TM 5-
2420-231-10) for approximately 10
minutes.
NOTE
Do not allow engine to become overheated during this procedure. If
coolant temperature gauge indicates high engine coolant temperature,
turn ignition switch off immediately.
24. Monitor and record coolant tem-
Coolant Temperature Gauge OK -
Troubleshooting complete.
perature (TM 5-2420-231-10).
Coolant Temperature Gauge
Indicates High Coolant Temperature
- Replace water pump (WP 0128).
Proceed to Test Step 9.
Test Step 7. Test Coolant
Temperature Sending Unit and
Signal Circuit for an Open.
1. Turn ignition switch to the off posi-
tion (TM 5-2420-231-10) and dis-
connect batteries (WP 0157).
2. Remove locknut (Figure 18,
Item 1) from coolant temperature
sending unit (Figure 18, Item 2)
and remove wiring harness con-
nector (Figure 18, Item 3) from
coolant temperature sender
(Figure 18, Item 2).
0021-22