TM-9-2540-207-14-P

HEATER, VEHICULAR COMPARTMENT, MODEL: A20

TECHNICAL MANUAL; OPERATOR, FIELD, AND SUSTAINMENT MAINTENANCE MANUAL INCLUDING REPAIR PARTS AND SPECIAL TOOLS LIST

JULY 2007

TM-9-2540-207-14-P - Page 194 of 288

TM 9-2540-207-14&P

6-30

DURING RUN OPERATIONS THE BURNER TEMPERATURE DROPS BELOW NORMAL OPERATING

LIMITS;- FLAME OUT DURNIG HIGH TO LOW

OR - XT BELOW FLAMEOUT THRESHOLD OR - BT

BELOW FLAMEOUT THRESHOLD OR - XT DROPPED MORE THAN 40C IN 8 SECONDS

CHECK/POSSIBLE CAUSE

REF

.R

EPAIR

12

CHECK WIRE HARNESS FOR

CONTINUITY AND SHORTS

CHECK 2 WIRES FROM THE VENT FAN BOARD

TO THE LOGIC BOARD FOR CONTINUITY AND

SHORT TO GROUND:

P11-PIN12 TO P1-PIN3

P11-PIN4 TO P1-PIN12

CHECK

FOR MV SIGNAL

BETWEEN

P11-PIN13 AND P11-PIN5 FOR BT SENSOR

P11-PIN14 AND P11-PI N 6 FOR XT SENSOR

CHECK FOR OPEN LINE BETWEEN

P11-PIN13 TO CHASIS GROUND AND

P11-PIN14 TO CHASIS GROUND

IF ANY CHECK FAILS

REPLACE WIRE HARNESS

RESTART HEATER

13

DEFECTIVE LOGIC BOARD

REPLACE LOGIC BOARD

RESTART HEATER

6.5.37 F3 - HEAT LIMIT (Design Iteration 1 & 2 Only)

VENT AIR OUTLET TEMPERATURE HAS EXCEEDED THE UPPER TEMPERATURE LIMITS OF

340°F (171°C) AND HEAT OUTPUT WILL BE REDUCED

CHECK/POSSIBLE CAUSE

REF

.R

EPAIR

1

CHECK THAT ALL DAMPERS IN

VEHICLE ARE OPEN

OPEN ALL DAMPERS FULLY

SWITCH HEATER TO LOW MODE

2

CHECK FOR OBSTRUCTIONS IN

FRONT OF HEATER VENTILATION

OUTLET

REMOVE OBSTRUCTIONS

SWITCH HEATER TO LOW MODE

3

CHECK ALL DUCTING

CONNECTIONS

VEHICLE TM

2.2

2.3

2.7

INSTALL DUCTING CORRECTLY

SWITCH HEATER TO LOW MODE

4

DEFECTIVE HEAT EXCHANGER

5.4.1

REPLACE HEAT EXCHANGER

RESTART HEATER