TM 5-5420-234-14&P
4-12. UNIT TROUBLESHOOTING (continued).
7.
HOURMETER DOES NOT OPERATE (MODEL A ONLY) (continued).
TEST OPTIONS
3.
KNOWN INFO
Voltage Test.
No voltage at junction
Are 2228 volts
box terminal strip.
measured at the cab
REASON FOR QUESTION
control box connector
POSSIBLE PROBLEMS
(J2), position D?
Power supply for the
hourmeter circuit comes
Cab control box faulty.
from the cab control box. If
Linking harness faulty.
no voltage is measured, the
Junction box harness
problem is internal to cab
faulty.
control box. If voltage is
LHS MODE SELECT
measured, the problem is
switch faulty.
outside the cab control box.
Go to Step 6.
NO
YES
4-124
Change 1
