TM 5-4520-253-13
Table 4-1. Intermediate Maintenance Troubleshooting – Continued
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 3.
If motor does not operate or operates slowly, check brushes, commutator, bear-
ings, and fan assemblies.
Clean motor and replace defective parts. Refer to REPAIR BLOWER
MOTOR, page 4-51.
Step 4. Test thermal motor protector at room temperature for continuity. Meter should
indicate zero resistance.
Replace defective protector. Refer to REMOVE/l NSTALL/TEST
THERMAL MOTOR PROTECTOR, page 4-44,
Step 5. Test individual capacitors for continuity. Meter should indicate zero
resistance.
Replace defective capacitors. Refer to REMOVE/l NSTALL/TEST
CAPACITORS, page 4-46.
Step 6. Test blower motor. Refer to DISASSEMBLE/ASSEMBLE/TEST BLOWER
MOTOR, TESTING, page 4-49.
If blower fails to displace at least 15 inches of water, replace blower
motor.
Refer to REMOVE/l NSTALL COMBUSTION BLOWER AND
HOUSING, page 4-40.
Step 7.
Inspect burner head for combustion deposits clogging air passages. Check con-
dition of internal baffles.
Replace damaged burner head.
No repairs, other than cleaning and
replacing gasket, are authorized.
Refer to REPAIR BURNER HEAD
ASSEMBLY, page 4-65.
4-4
