C4, TM 9-2350-230-12
TABLE 8-11. FUEL LEVEL INDICATOR CIRCUITS (FIG. 8-8)
CAUTION: Disconnect battery positive and negative cables before making tests.
NOTE. Tanks must have at least 36 gallons of total fuel for purposes of these tests. Upper tank valves
must be open.
CIRCUIT
TEST POINTS
RESISTANCE
COMPONENT
NUMBER FROM
TO
(ohms)
CIRCUIT
REMARKS
Power circuit
31C
P6
P5J
0
Through circuit
Infinity indicates open
to panel
breaker to panel
circuit breaker or
defective lead.
Power circuit to
32C
P5F
P1
0
Panel to lower
Infinity indicates open
transmitters
transmitter
circuit, defective lead
or blown fuse.
Power circuit in
---
P11J
P11F
0
Through jumper in
Resistance indicates
panel
panel
defective panel.
Fuel level
---
P11E
P9
350
Through indicator to
Infinity indicates open
indicator
ground
circuit in panel.
Fuel level
---
P11E
P11F
350
Through indicator to
Infinity indicates open
indicator
ground
circuit in panel.
Mounting bracket
---
PANEL
HULL
0
Mount ground lead
Infinity indicates open
ground lead.
Upper trans-
32A
P4
P5E
0
Upper transmitter to
Infinity indicates open
mitter to panel
indicator panel
circuit or defective lead.
lead
Lower trans-
---
P1
P2
45
Through lower
Zero resistance
mitter
transmitter
indicates lost float.
Upper trans-
---
P3
P10
385
Through upper
Low resistance indi-
mitter
transmitter
cates shorted trans-
mitter resistor. Infinity
indicates open resistor.
Upper Trans-
-- (a)
P3
P4
5-385
Through part of
mitter
zero OHMS at empty to
385 OHMS at full. Zero
OHMS indicates lost
float.
-- (b)
P4
P10
0-385
Balance of resistor
Total resistance,(a) +
(b)
should
equal
approx-
imately 385 OHMS.
Low
cates shorted resistor.
Transmitter
30
P10
HULL
0
Through circuit
Resistance indicates
ground circuit
groun
#30 to ground
poor ground connection
d
to bulkhead. Infinity
indicates open ground
circuit.
Transmitter
32B
P2
P3
0
Lower transmitter to
Infinity indicates open
interconnector
upper transmitter
circuit or defective lead.
TEMPORARILY DISCONNECT LEAD #32B AT P3. THEN:
Transmitters
---
P1
P10
Infinity
Through lower trans-
Reading other than
mitter resistor to
infinity indicates lower
ground,
shorted.
8-59
C9, TM 9-2350-230-12