TM 5-2420-231-23-1
0030
Table 1. Heating and A/C Troubleshooting Procedures - Continued.
030
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
1. Heater Does Not Blow
8. Remove front instrument panel
Warm Air When
right-side cover (WP 0176).
Temperature Control Is
9. Inspect heater tubes (Figure 11,
Heater Tubes OK - Proceed to step 9.
Set to Maximum Heat -
Item 2) for Class III leaks, cracks,
Class III Leaks Present at Heater
Continued
dents, or kinks.
Tubes - Replace heater tubes (WP
0354).
Proceed to Test Step 6.
Heater Tubes Cracked, Dented, or
Kinked - Replace heater tubes (WP
0354).
Proceed to Test Step 6.
10. Inspect heater inlet hose (Figure
Heater Hose and Clamps OK -
11, Item 5) and heater outlet hose
Proceed to step 11.
(Figure 11, Item 8) for Class III
Class III Leaks Present at Heater Inlet
leaks, loose or broken clamps (Fig-
or Heater Outlet Hose - Replace
ure 11, Items 1, 4, 6, and 7),
clamps. If hose continues to leak,
cracks, kinks, sharp bends, col-
replace heater hose (WP 0354).
lapsed areas, or restrictions.
Proceed to Test Step 6.
Heater Hose Clamp Loose - Replace
clamp (WP 0354).
Proceed to Test Step 6.
Heater Hose Cracked, Kinked,
Sharply Bent, Collapsed, or
Restricted - Straighten or replace
heater hose (WP 0354).
Proceed to Test Step 6.
11. Ensure that heater control cable
Heater Control Cable OK - Proceed to
(Figure 11, Item 3) is not bent,
step 12.
kinked, or damaged, and that it is
Heater Control Cable Bent, Kinked,
connected to heater control valve
or Damaged - Replace heater control
(Figure 11, Item 9).
cable (WP 0357).
Install cab floor cover plate (WP 0306).
Proceed to Test Step 6.
0030-14
