TM 9-2320-260-34-2
17-12. ENGINE COOLANT HEATER TESTING (Contd)
2.
Remove four screw-assembled lockwashers (2) and guard (1) from heater (9). Discard screw-
assembled lockwashers (2).
Disconnect lead (16) from 24-volt power source (17).
3.
4.
Remove screw-assembled lockwasher (11) and igniter lead (12) from flame detector switch (10).
Discard screw-assembled lockwasher (11).
Disconnect fuel control valve leads (6) and (8) from overheat switch (7).
5.
6.
Connect hose (4) to bleed screw (13) on fuel control valve (3) and place other end of hose (4) in
container (5).
Open two fuel shutoff valves (14).
7.
NOTE
Have drainage container ready to catch fuel.
Connect lead (16) to power source (17).
8.
Ensure switch (21) is in LO position. Place switch (19) in START position and hold. Open bleed
9.
screw (13) and let fuel flow until no air bubbles are observed in fuel flowing into container (5).
Place switch (19) in OFF position. Close bleed screw (13).
10.
Disconnect lead (16) from power source (17).
11,
Install igniter lead (12) on flame detector switch (10) with new screw-assembled lockwasher (11).
12.
13.
Connect fuel control valve leads (6) and (8) on overheat switch (7).
Open coolant shutoff valve (15).
14.
15.
Check for signs of coolant leaks. Tighten loose connections or replace damaged parts if leaking
Close coolant shutoff valve (15).
16.
17.
Connect lead (16) to power source (17).
b. Igniter Test
NOTE
Ignition time is the interval from activating control box switch to
START position until indicator lamp illuminates.
1. Place switch (19) in START position and hold. Record time interval fromactivating switch (19)
until indicator lamp (20) illuminates. During this time interval, record ignition amperage on
multimeter (18).
2. If ignition time exceeds three minutes, or if ignition amperage exceeds 15 amperes, check fuel flow
components (paras. 17-3 through 17-11, as necessary).
3. Place switch (19) in OFF position.
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