TM 9-2350-230-12
TABLE 8-13. BILGE PUMP CIRCUITS (FIG. 8-10)
CIRCUIT
TEST POINTS
RESISTANCE
COMPONENT
NUMBER
FROM TO
(ohms)
CIRCUIT
REMARKS
CAUTION: Disconnect battery positive and negative cables before making resistance or continuity tests.
Main bilge sys-
111
P1
P2-C
0
Circuit from master
Infinity indicates open
tem electrical
111
P1
P2-D
0
relay to the switch
circuit or defective
feed
723
P1
P4-B
0
panel and both bilge
lead.
722
P1
P5-B
0
pump relays
Front bilge
721
P2-D
P3-E
0 OR INF
Circuit through
Front bilge pump
pump switch
switch and panel
switch "on":
Infinity indicates open
circuit, defective
leads or switch.
Front bilge pump
switch "off": Zero
OHMS indicates de-
fective switch or
short circuit.
Front bilge
721L
P2-D
GND
170-210
Circuit through
Front bilge pump
pump indicator
switch panel and
switch "on":
light
light bulb
Infinity indicates open
circuit, defective leads
or burned out light
bulb. Zero OHMS in-
dicates a short circuit.
Front bilge
721-
P3-E
P4-A
0
Circuit from switch
Infinity indicates open
pump panel to
721A
panel to relay
circuit or defective
relay lead
lead.
Front bilge
723A
P4-C
P6
0
Circuit from relay
Infinity indicates open
pump relay to
through circuit
circuit, defective lead
pump lead
breaker to pump
or circuit breaker.
Front bilge pump
723B
P6
GND
35-. 70
Circuit through pump
Resistance variation
greater than .70 OHMS
or less than .35 OHMS
indicates defective
pump.
Rear bilge pump
721B
P2-C
P2-B
0 OR INF
Circuit through
Rear bilge pump switch
switch
switch and panel
"on": Infinity indicates
open circuit, defective
leads or switch.
Rear bilge pump switch
"off": Zero OHMS in-
dicates defective switch
or short circuit.
Rear bilge pump
721BL
P2-B
GND
170-210
Circuit through
Rear bilge pump switch
indicator light
switch panel and
"off": Infinity indicates
light bulb
open circuit, defective
leads or burned out
bulb. Zero OHMS in-
dicates a short circuit.
Rear bilge pump
721B
P2-B
P5-A
0
Circuit from switch
Infinity indicates open
panel to relay
panel to relay
circuit or defective
lead
lead.
8-63
