TM 9-4120-385-14
4-8. TROUBLESHOOTING Continued
Table 4-2. TROUBLESHOOTING FOR UNIT MAINTENANCE
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Check heater thermostatic switch S3.
Replace S3 if defective. Refer to Paragraph 4-25.
Step 4. Check mode selector switch S.
Replace if defective. Refer to Paragraph 4-18.
WARNING
Allow heater elements to COOL before handling. Severe bums can
result from touching heater elements.
Step 5. Check heater elements.
Replace if defective. Refer to Paragraph 4-26.
WARNING
High voltage in air conditioner can kill.
Step 6. Check wiring for loose or broken connections. Refer to wiring diagram
(FO-1).
Repair or replace as necessary. Refer to Paragraph 4-23.
4. LITTLE OR NO ADDITIONAL HEATING IN HI HEAT MODE
Step 1. Check that mode selector switch S is positioned for HI HEAT operation.
Set controls for HI HEAT operation.
Step 2. Check that temperature selector switch S1 is set to extreme INCREASE
position.
Set temperature selector switch to maximum INCREASE setting by
rotating clockwise.
4-19
