TM-9-2320-279-20-1

M977 SERIES, 8x8 HEAVY EXPANDED MOBILITY TACTICAL TRUCKS (HEMTT)

TECHNICAL MANUAL; MAINTENANCE INSTRUCTIONS; ORGANIZATIONAL MAINTENANCE, VOLUME 1 OF 3

TM-9-2320-279-20-1 - Page 151 of 985

TM 9-2320-279-20-1

Troubleshooting Malfunctions (Cont)

Tab/e 2-9. Troubleshooting (Cont)

Change 3

2-66.1/(2-66.2 blank)

Malfunction

Test or Inspection

Corrective Action

Step 1.

Check for defective engine speed control wiring. Disconnect plug from engine high idle as-

sembly. Set multimeter to test for 24 Set

Set ENGINE and PTO ENGAGE switches to ON

and crane POWER

switch to OFF. Place

negative (-) probe in socket No. 4 and touch posi-

tive (+) probe to PIN No. 1. Meter

should

show 24 vdc.

If meter does not show 24 vdc, trace wiring and find problem. Refer to FO-1, Electric

Diagram.

Step 2.

Check for defective crane power wiring. Disconnect plug from engine high idle assembly,

Set

multimeter

to test

for 24 vdc. Set

crane POWER switch to ON. Place negative (-)

probe

in

socket No. 4 and

positive (+) probe to PIN No. 2. Meter should show 24 vdc.

If meter does not show 24

vdc, repair No. 310 wire to crane junction box. If problem

is not solved, report problem to the supervisor.