TM 5-3610-253-14
Table 5-9. DIRECT/GENERAL SUPPORT TROUBLESHOOTING - Cont
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
14.
BACKGAUGE DOES NOT OPERATE ELECTRICALLY IN THE BACKWARD DIRECTION.
Step 1.
Check operation of contactor and relay c15 as follows:
a. Remove the front electronics enclosure cover.
b. Remove cover to relay c15 on PC card ST. Check that the resistance of
the coil is between 804 and 836 ohms.
(a) If resistance is incorrect, replace defective relay.
(b) If resistance is correct, proceed to step 2.
WARNING
Electrical shock hazard. You must stand on rubber matting as a protective
measure before performing this procedure. Death or serious injury may
occur.
Step 2.
Check operation of backgauge control switch b10 as follows:
a.
Turn main power switch to I position.
b.
Press control power on switch.
Check for 42 V ac at plug connector ST 21 pin 2, using plug connector ST
c.
6 pin 8 as ground.
(a) If voltage is missing, replace backgauge control switch
(b) If voltage is present, proceed to step 3.
Check for 42 V ac at plug connector ST 21, pin 5, using plug
Step 3.
connector ST 6 pin 8 as ground.
(a) If voltage is missing, replace backgauge backward motion
limit switch b13 (paragraph 5-16.9).
(b) If voltage is present, proceed to step 4.
