TM 5-3805-254-20-1
ORGANIZATIONAL TROUBLESHOOTING - CONTINUED
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
1. ENGINE CRANKS BUT FAILS TO START BELOW 50°F (18°C) - CONTINUED.
WARNING
Although KEY SWITCH must be on and battery ground cable connected to test electrical
circuit voltage, turn off KEY SWITCH and disconnect battery ground cable before doing
resistance tests or replacing parts. This will keep you from getting shocked and prevent
damage to parts and equipment.
Step 2.
Set multimeter to 20 vdc scale. Connect red test lead to glow plug terminal (1)
and black test lead to ground. Have assistant press GLOW PLUG ON/OFF switch
(2) to ON position. Check for 11 to 13 vdc on multimeter. Have assistant push
GLOW PLUG ON/OFF switch (2) to OFF position. Disconnect test leads.
a. If multimeter does not read 11 to 13 vdc go to step 4.
b. If multimeter reads 11 to 13 vdc, go to step 3.
Step 3.
Check glow plug (3) as follows: Using 3/8-inch open-end wrench, unscrew and
take off nut (4) and wire (5) from glow plug terminal (1). Using 7/8-inch open-
end wrench, unscrew and take glow plug (3) out of housing (6). Set multimeter
to ohms scale and adjust to 0 ohms. Connect red test lead to glow plug terminal
(1) and black test lead to glow plug body (7). Check for test lead to glow plug
body (7). Check for 0 ohms on multimeter. Disconnect test leads.
a. If multimeter reads no continuity, replace glow plug
(page 2-512).
b. If multimeter reads 0 ohms, screw glow plug (3) into housing (6)
and tighten using 7/8-inch open-end wrench. Place wire (5) in
position and screw nut (4) on to glow plug terminal (1). Tighten
using 3/8-inch open-end wrench and go to step 19.
Step 4.
Unscrew and take out two wing screws (8) and take off junction box cover (9).
Set multimeter to 20 vdc scale. Connect red test lead to terminal stud (10) on
junction box (11) and black test lead to ground. Have assistant press GLOW
PLUG ON/OFF switch (2) to ON position. Check for 11 to 13 vdc on multimeter.
Have assistant press GLOW PLUG ON/OFF swich (2) to OFF position. Disconnect
test leads.
a. If multimeter does not read 11 to 13 vdc, go to step 6.
b. If multimeter reads 11 to 13 vdc, go to step 5.
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