TM 9-2320-260-20
Table 2-4. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
Open tachograph.
Step 9.
Increase engine speed to 2400 rpm and maintain.
Step 10.
Touch positive lead of multimeter to contact end of lead 27 at red lamp.
Step 11.
Touch negative lead of multimeter to frame ground. Voltage should be present and lamp
Step 12.
should light.
a. If voltage is present, go to step 13.
b. Replace tachograph if voltage is not present (para. 14-49).
Touch positive lead of multimeter to contact end of clear lamp.
Step 13.
Touch negative lead of multimeter to frame ground. Voltage should be present and lamp
Step 14.
should light.
a. If voltage is present, go to step 15.
b. Replace tachograph if voltage is not present (para. 14-49).
Remove two lamps (para. 14-49).
Step
15.
Set multimeter to RX1 scale.
Step
16.
Touch positive lead of multimeter to contact end of red lamp.
Step
17.
Touch negative lead of multimeter to contact end at side of lamp. Continuity should be
Step
18.
present.
a. Adjust engine rpm warning contact if continuity is present (para. 14-49).
b. Replace lamps if continuity is not present (para. 14-49).
Touch positive lead of multimeter to contact end of clear lamp.
Step 19.
Touch negative lead of multimeter to contact end at side of lamp. Continuity should be
Step 20.
present.
a. Adjust engine rpm warning contact if continuity is present (para. 14-49).
b. Replace lamps if continuity is not present (para. 14-49).
END OF TESTING!
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