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 180 of 288
TM 9-2540-207-14&P
6-16
6.5.21 E1 - LOW VOLTAGE (Design Iteration 1 & 2 Only)
VOLTAGE SUPPLIED TO THE HEATER IS BELOW NORMAL VOLTAGE LIMITS (19VDC - 28VDC
NORMAL RANGE)
CHECK/POSSIBLE CAUSE
REF
.R
EPAIR
1
CHECK THE SOURCE VOLTAGE OR
BATTERY LEVELS.
IF VOLTAGE IS LESS THAN 19VDC THEN OPERATE
HEATER WITH VEHICLE RUNNING
2
WITH HEATER OFF, CHECK FOR
FREE ROTATION OF THE VENT
IMPELLER BY MANUALLY SPINNING
BY HAND
5.2.6
5.2.4
IF IMPELLER DOES NOT SPIN FREELY, REPLACE
VENT FAN MOTOR AND VENT FAN IMPELLER
RESTART HEATER
3
CHECK ELECTRICAL INPUT
CONNECTIONS FOR LOOSE WIRES
2.5
5.5.6
RECONNECT ALL ELECTRICAL CONNECTIONS TO
WIRING HARNESS
RESTART HEATER
4
DEFECTIVE ELECTRONIC VENT FAN
DRIVER BOARD
5.2.5
REPLACE ELECTRONIC VENT
FAN DRIVER BOARD
RESTART HEATER
5
DEFECTIVE WIRING HARNESS
5.5.6
REPLACE WIRING HARNESS
RESTART HEATER
6.5.22 E1 - LOW VOLTAGE (Design Iteration 3 Only)
VOLTAGE SUPPLIED TO THE HEATER IS BELOW NORMAL VOLTAGE LIMITS (19VDC-28VDC
NORMAL RANGE); LOW VOLTAGE OR LOW VOLTAGE IN VENT ONLY
CHECK/POSSIBLE CAUSE
REF
.R
EPAIR
1
CHECK THE SOURCE VOLTAGE OR
BATTERY LEVELS.
IF VOLTAGE IS LESS THAN 19VDC THEN OPERATE
HEATER WITH VEHICLE RUNNING
2
CHECK POWER INLET SIDE OF THE
START/OFF/RUN SWITCH TO HAVE
GREATER THAN 19 VDC
IF VOLTAGE IS LESS THAN 19VDC THEN OPERATE
HEATER WITH VEHICLE RUNNING
3
CHECK THAT THE PROPER GAUGE
OF WIRE IS USED FOR THE LENGTH
OF CIRCUIT.
REQUIREMENT IS 12 AWG FOR <12 FT; FOR
LONGER CIRCUITS THE RESISTANCE MUST BE LESS
THAN OR EQUAL TO 12 AWG @12FT.
INSTALL PROPER GAUGE OF SUPPLY WIRE
RESTART HEATER
4
CHECK ELECTRICAL INPUT
CONNECTIONS FOR LOOSE WIRES
RECONNECT ALL ELECTRICAL CONNECTIONS TO
HEATER
RESTART HEATER
5
CHECK VOLTAGE ON OUTLET SIDE
OF FILTER BOARD WITH POWER
SUPPIED TO HEATER
VOLTAGE BETWEEN GROUND (J2-PIN1) AND HOT
WIRE (J2-PIN3) SHOULD EQUAL THE VOLTAGE
SUPPLIED
IF THE VOLTAGE IS LOW
REPLACE THE FILTER BOARD
RESTART HEATER
6
CHECK VOLTAGE AT THE POWER
BOARD INLET
VOLTAGE BETWEEN GROUND (J7) AND HOT WIRE
(J2) SHOULD EQUAL THE VOLTAGE SUPPLIED
IF THE VOLTAGE IS LOW
REPLACE THE POWER BOARD
RESTART HEATER
Back to Top
