TM 9-2320-387-24-l
PROTECTIVE CONTROL BOX
6~0~
12.y
DIAGNOSTIC FLOWCHART
KNOWN INFO
BATTERIES OK
LEAD 578 GROUND OK
POSSIBLE PROBLEMS
PARKING BRAKE SWITCH BAD
BODY HARNESS WIRES BAD
~
GLOW PLUG CONTROLiER
~ BAD
~
ALTERNATOR BAD
HARNESS WIRE 2A BAD
IGNlTlON SWITCH BAD
HARNESS WIRE 29A BAD
HARNESS WIRE 29C BAD
PROTECTIVE CONTROL
BOX BAD
LEAD 578 GROUND OK
IGNlTlON SWITCH OK
HARNESS WIRE 29A OK
HARNESS WIRE 29C OK
POSSIBLE
PROBLEMS
PARKING BRAKE SWITCH
BAD
BODY HARNESS WIRES BAD
GLOW PLUG CONTROLLER
BAD
ALTERNATOR BAD
HARNESS WIRE 2A BAD
PROTECTIVE CONTROL
BOX BAD
KNOWN INFO
BATTERIES OK
LEAD 578 GROUND OK
IGNITION SWITCH OK
HARNESS WIRE 29A OK
HARNESS WIRE 29C OK
POSSIBLE
PROBLEMS
PARKING BRAKE SWITCH
BAD
BODY HARNESS WIRES BAD
GLOW PLUG CONTROLLER
BAD
ALTERNATOR BAD
HARNESS WIRE 2A BAD
PROTECTIVE CONTROL
BOX BAD
IS LED 13 ON?
IF ENGINE IS AT OPERATING
TEMPERATURE, LED 13 WILL
NOT COME ON.
r OPTlONS
1. TRY IT.
2. VISUAL
REASON FOR QUESTlON
If this LED is not ON, that would
indicate either malfunctioning
ignition
switch, damaged harness wires 29A
and 29C, or malfunctioning PCB.
IS LED 5 ON?
VISUAL
I
REASON FOR QUESTION
If this LED is not ON, that would
indicate PCB malfunctions.
IS LED 6 ON?
if OPTIONS
VISUAL
BRAKE SWITCH AND/
REASON FOR QUESTION
If this LED is not ON, that would
indicate a parking brake switch
malfunction or damage to body
harness wires.
