TM 5-4520-241-14
Table 4-2. Organizational Maintenance Troubleshooting - Continued
MALFUNCTION
TESTING OR INSPECTION
CORRECTIVE ACTION
5 - Continued
washers (2 and 3) and pull out assembled switch and bracket (4 through 8). Remove screws (4)
and washers (5 and 6) securing flame switch (8) to mounting base (7). Pull off defective switch.
No repair is possible. Install a new switch by reversing the removal procedure. Make sure tip of
switch probe engages bracket on heat exchanger.
6.
HEATER IGNITES, BUT VENTILATING MOTOR FAILS TO RUN.
Step 1.
Check power to ventilating motor. Connect power plug. Move HEATER-OFF-FAN switch to FAN.
If fan runs, proceed to step 2. If fan fails to run, proceed to step 3.
Step 2.
Check wiring from flame switch to motor. Orange wire from flame switch and orange wire from
motor connect at same terminal on terminal strip.
Tighten loose connections or replace broken wires.
Step 3.
With conditions in step 1, check for 120 volts at motor terminals.
If there is no power, tighten loose connections or replace broken wires.
7.
HEATER BACKFIRES.
Step 1.
Check for correct fuel adjustment.
Adjust fuel needle as follows:
Start the heater and allow it to warm up for a few minutes.
Open the front access door and turn the fuel needle (fig. 4-10) clockwise gently until it is seated in
the carburetor body.
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