TM-9-2320-361-24-2 Field Maintenance Manual Volume 2 for M44A2 Series Trucks
Page 896 of 1144
TM 9-2320-361-24-2 0435 00 0435 00-4 FUEL BURNING PERSONNEL HEATER TESTING (Contd) PREPARATION (Contd) 2. Turn two fasteners (11) and remove guard (5) from heater (13). 3. Disconnect lead (18) from 24-volt power source (20). 4. Disconnect igniter lead (7) from ignition control unit (6). 5. Remove nut-assembled lockwasher (1), shutoff valve lead (2), nut-assembled lockwasher (15) and thermostat lead (14) from overheat switch (3). Discard nut-assembled lockwashers (1) and (15). 6. Connect hose (10) to bleed screw (8) on fuel control valve (9) and place other end of hose (10) in container (12). 7. Connect lead (18) to 24-volt power source (20). 8. Open fuel shutoff valves (17). NOTE Have drainage container ready to catch fuel. 9. Place switch (23) in LO position. Place switch (21) in START position and hold. Open bleed screw (8) and let fuel flow from bleed screw (8) until no air bubbles are observed in fuel. 10. Place switch (21) in OFF position. Close bleed screw (8). 11. Install thermostat lead (14) and shutoff valve lead (2) on overheat switch (3) with new nut-assembled lockwasher (15) and (1). 12. Connect igniter lead (7) on ignition control unit (6). NOTE Ignition time is the interval from activating control box switch to START position until indicator lamp illuminates. 13. Place switch (21) in START position and hold. Record time interval from activating switch (21) until indicator lamp (22) illuminates. During this time interval, record ignition amperage on meter (19). Place switch (21) in OFF position. 14. If ignition time exceeds three minutes, or if ignition amperage exceeds 15 amperes, check fuel flow and replace damaged parts (WP 0426 00–WP 0435 00), as necessary. FLAME DETECTOR SWITCH TEST 1. Place switch (21) in START position. 2. When indicator lamp (22) illuminates, place switch (21) in RUN position. 3. If indicator lamp (22) does not light adjustor, replace flame detector switch (4) (WP 0431 00). 4. Place switch (21) in OFF position. FUEL CONTROL VALVE TESTING 1. Place switch (21) in START position. 2. When indicator lamp (22) illuminates, place switch (21) in RUN position. 3. Check fuel consumption at flowmeter (16). Fuel consumption should be 10-13 cc/min at low heat, and 19-24. cc/min at high heat. If fuel consumption rate is not within limits, replace fuel control valve (9) (WP 0428 00). 4. Check operating amperage at ammeter (19). If operating amperage exceeds 10 amperes, check heater wiring and replace damaged parts (WP 0426 00–WP 0435 00), as necessary. 5. Place switch (21) in OFF position.