TM 5-6115-590-12
Table 4-2. Troubleshooting
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
ENGINE
1.
FUEL BOOST PUMP/MOTOR ASSEMBLY FAILS
TO RUN.
Step 1.
Check starting procedure.
Review preparation for starting procedures
in paragraph 2-10a.
Step 2.
Check specific gravity of electrolyte in batteries.
Recharge or replace batteries as indicated or
use an external power source.
Step 3.
Check cables and batteries for corrosion or
loose connection.
Clean battery cables or connect battery
cables. (fig. 4-1)
Step 4.
Check for low or depleted fuel supply.
Replenish fuel supply.
Step 5.
Check
for
incorrect
or
loose
electrical
connections to fuel boost pump motor.
Tighten or replace connections (fig. 4-34)
Step 6.
Check continuity between switch poles of master
switch (S1) with power supply off and switch on.
If no continuity, replace master switch. (fig.
4-21)
Step 7.
Check to see if circuit breaker (CB1) has tripped.
Reset circuit breaker. Replace failed circuit
breaker. (fig. 4-21)
Step 8.
Check fuel boost pump switch (S8).
Replace switch. (fig. 4-21)
Step 9.
Check air intake door switch (S4).
Replace switch.
Step 10. Check shunt (R1).
Replace shunt. (fig. 4-37)
Step 11. Check boost pump motor.
Replace boost pump motor. (fig. 4-34)
2.
NO RESPONSE WHEN MASTER SWITCH (S1) IS
PLACED IN START POSITION.
Step 1.
Check starting procedure,
Start procedure is correct. (Para. 2-10)
Proceed to Step 2.
Step 2.
Check specific gravity of electrolyte.
Recharge or replace batteries.
Stop 3.
Check cables for corrosion or loose connection.
Clean or connect battery cables. (fig. 4-1)
Step 4.
Check circuit breaker (CB1).
Reset or replace circuit breaker. (fig. 4-21)
Step 5.
Check master switch (S1).
Replace switch. (fig. 4-21)
Step 6.
Check intake door switch (S4)
Replace failed switch
Step 7.
Check electrical connections to start motor.
Tighten or replace electrical connections as
indicated. (fig. 4-43)
Step 8.
Check cables.
Replace starter cables. (fig 4-43)
Step 9.
Check relay (K1).
Replace relay. (fig. 4-39)
Step 10. Check 400 Hz main contactor switch (S2).
Place switch in open position or replace
switch. (fig. 4-21)
Step 11. Check 60 Hz output contactor switch (S3).
Place switch in output position or replace
switch. (fig. 4-21)
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Step 12. Check centrifugal multispeed switch assembly overspeed
110 percent switch or 35 percent switch.
Replace multispeed switch. (fig 4-43)
Step 15. Check start motor assembly.
Replace starter. (fig. 4-43)
Step 14. Check time delay relay (K4).
Replace relay (fig. 4-37).
3.
START MOTOR RUNS BUT DOES NOT ROTATE ENGINE.
Check start motor assembly.
Replace starter (fig. 4-43)
4.
ENGINE STOPS MOTORING WHEN MASTER SWITCH IS
RELEASED FROM START POSITION.
Step 1.
Check switch (S1).
Replace master switch. (fig. 4-21)
Step 2.
Check start relay (K1).
Replace relay. (fig. 4-39)
Step 3.
Check holding relay (K3).
Replace relay. (fig. 4-37)
5.
START MOTOR FAILS TO SHUT OFF WHEN ENGINE
REACHES 35 PERCENT OF GOVERNED SPEED.
Step 1.
Check start relay (K1).
Replace relay. (fig. 4-39)
Step 2.
Check centrifugal multispeed switch assembly 35
percent switch.
Replace centrifugal multispeed assembly. (fig. 4-43)
6.
ENGINE MOTORS BUT COMBUSTION DOES NOT OCCUR.
Step 1.
Check specific gravity of electrolyte.
Recharge or replace batteries as indicated.
Step 2.
Check for low or depleted fuel supply.
Replenish fuel supply.
Step 3.
Check for cloggedfuel lines of filters.
Replace fuel filters as indicated. (fig. 4-45)
Step 4.
Check fuel control assembly.
Replace fuel control assembly. (fig. 4-44)
Step 5.
Check fuel boost pump and motor assembly.
Replace fuel boost pump and motor. (fig. 4-34)
Step 6.
Check fuel atomizer.
Clean screen or replace fuel atomizer assembly. (fig.
4-50)
Step 7.
Check for actuation of fuel solenoid valve.
Replace solenoid valve. (fig. 4-45)
Step 8.
Check oil supply.
Replenish oil supply.
Step 9.
Check oil pump pressure relief valve.
Replace pressure relief valve. (fig. 4-47)
Step 10. Check oil pressure sequencing switch.
Refer to paragraph 4-70d for adjustment procedure.
Replace failed sequencing switch. (fig. 4-41)
4-21
