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
12. Remove right blower duct (WP
Warm Air When
0350).
Temperature Control Is
13. Inspect cab heater inlet hose (Fig-
Cab Heater Hose and Clamps OK -
Set to Maximum Heat -
ure 12, Item 4) and cab heater out-
Proceed to step 14.
Continued
let hose (Figure 12, Item 5) for
Class III Leaks Present at Cab Heater
Class III leaks, loose or broken
Inlet or Heater Outlet Hose - Replace
clamps (Figure 12, Item 3), cracks,
clamps. If hose continues to leak,
kinks, sharp bends, collapsed
replace cab heater hose (WP 0353).
areas, or restrictions.
Proceed to Test Step 6.
Cab Heater Hose Clamp Loose -
Replace clamp (WP 0353).
Proceed to Test Step 6.
Cab Heater Hose Cracked, Kinked,
Sharply Bent, Collapsed, or
Restricted - Straighten or replace cab
heater hose (WP 0353).
Proceed to Test Step 6.
14. Inspect cab heater tubes (Figure
Cab Heater Tubes OK - Proceed to
12, Item 2) for Class III leaks,
step 15.
cracks, dents, kinks, or restric-
Class III Leaks Present at Cab Heater
tions.
Tubes - Replace heater tubes (WP
0353).
Proceed to Test Step 6.
Cab Heater Tubes Cracked, Kinked,
Sharply Bent, or Restricted - Remove
restriction or replace cab heater tubes
(WP 0353).
Proceed to Test Step 6.
15. Inspect cab heater tube hoses
Cab Heater Tube Hoses and Clamps
(Figure 12, Item 6) for Class III
OK - Replace cab heat exchanger
leaks, loose or broken clamps (Fig-
(Figure 12, Item 8) (WP 0352).
ure 12, Items 1 and 7), cracks,
Proceed to Test Step 6.
kinks, collapsed areas, or restric-
Class III Leaks Present at Cab Heater
tions.
Tube Hoses - Replace clamps. If hose
continues to leak, replace cab heater
tube hose (WP 0353).
Proceed to Test Step 6.
Cab Heater Hose Clamp Loose -
Replace clamp (WP 0353).
Proceed to Test Step 6.
0030-16
