TM 9-6115-729-24
0011
TROUBLESHOOTING FAILURES WITHOUT FAULT CODES - Continued
SYMPTOM
16.
Undesirable Speed Decrease With Load Increase.
MALFUNCTION
Improper Engine Operation.
CORRECTIVE ACTION
STEP 1.
On EMCP set ENGINE CONTROL switch to OFF/RESET. Set Battery
Disconnect Switch to OFF. Set DEAD CRANK SWITCH to OFF.
STEP 2.
On resistor assembly A7 Verify position of ISOCHRONOUS/DROOP switch
(TM 9-6115-729-10, WP 0006) and (FO-4, sheet 5).
STEP 3.
If in DROOP mode, go to step 4.
STEP 4.
On load resistor assembly A7 measure continuity between A7-2 and A7-1 (FO-4,
sheet 4). There should be no continuity. If continuity exists, replace
ISOCHRONOUS/DROOP switch (WP 0042).
STEP 5.
If ISOCHRONOUS/DROOP switch is good, keep switch in DROOP and go to
step 10.
STEP 6.
Place ISOCHRONOUS/Droop Switch in ISOCHRONOUS mode.
STEP 7.
On load resistor assembly A7 measure continuity between A7-2 and A7-1 (FO-4,
sheet 4). There should be continuity. If continuity does NOT exist, replace
ISOCHRONOUS/DROOP switch (WP 0042). If ISOCHRONOUS/DROOP switch
is good, go to step 8.
STEP 8.
Disconnect wires from LSM A4-13 (137A18,) and LSM A4-14 (139A18.) Set
Battery Disconnect Switch to ON. Set DEAD CRANK SWITCH to NORMAL. On
EMCP set ENGINE CONTROL switch to START. On EMCP set Contactor
Control Switch (CCS) to Close. Verify AC Circuit Interrupter Lamp is illuminated.
STEP 9.
Check for continuity between LSM A4 wires 137A18 and 139A18.
a. If continuity is present, proceed to step 10.
b. If continuity is not present, replace main load contactor K1 (WP 0048).
STEP 10.
Reconnect wire 137A18 to LSM A4-13; reconnect wire 139A18 to LSM A4-14.
Operate set in ISOCHRONOUS mode. Apply load.
a. Problem caused by improper engine operation. Engine may not be
developing enough horsepower.
b. Go to Low power/poor or no response to throttle troubleshooting procedure
(SYMPTOM 22).
STEP 11.
Set ISOCHRONOUS/DROOP switch to DROOP.
STEP 12.
Note position of droop potentiometer on LSM A4.
0011-18
