TM 5-5420-234-14&P
4-12. UNIT TROUBLESHOOTING (continued).
7.
HOURMETER DOES NOT OPERATE (MODEL A ONLY) (continued).
6.
KNOWN INFO
TEST OPTIONS
Is LED D59 in the cab
Visual inspection.
No voltage at junction
control box illumi-
box terminal strip.
REASON FOR QUESTION
nated?
No voltage at cab control
box, position D.
If the LED is out, it
indicates there is no
POSSIBLE PROBLEMS
power from the LHS
Cab control box faulty.
MODE SELECT switch.
LHS MODE SELECT
If the LED is on, there is
switch faulty.
an open circuit in the
hourmeter portion of the
cab control box.
Replace LHS selector
NO
switch (para 4-71).
Repair cab control
YES
box (para 4-71).
4-130
Change 1
