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
Test Step 5. Inspect Heater Shutoff
Warm Air When
Valve and Heater Hoses.
Temperature Control Is
WARNING
Set to Maximum Heat -
Continued
Allow engine to cool before performing procedure. Hot engine can cause
severe burns. Wear eye, hand, and skin protection when working with
heated parts.
Engine coolant is very slippery. Immediately wipe up any spills.
Failure to follow these warnings may result in injury or death to
personnel.
1. Ensure heater shutoff valve (Fig-
Heater Shutoff Valve Open - Proceed
ure 9, Item 2) is fully open.
to step 2.
Heater Shutoff Valve Closed - Fully
open heater shutoff valve.
Proceed to Test Step 6.
2. Inspect heater inlet hose (Figure 9,
Heater Hose and Clamps OK -
Item 5) and heater outlet hose
Proceed to step 3.
(Figure 9, Item 4) for Class III
Class III Leaks Present at Heater Inlet
leaks, loose clamps (Figure 9,
or Heater Outlet Hose - Tighten or
Items 1 and 3), cracks, kinks,
replace clamps. If hose continues to
sharp bends, or collapsed areas.
leak, replace heater hose (WP 0354).
Proceed to Test Step 6.
Heater Hose Clamp Loose - Tighten or
replace clamp.
Proceed to Test Step 6.
Heater Hose Cracked, Kinked
Sharply Bent, or Collapsed -
Straighten or replace heater hose (WP
0354).
Proceed to Test Step 6.
0030-10
