REFERENCE INFORMATION
The glowplugs first come ON when the engine
temperature is below 120 °F (49 °C) and the rotary switch
is turned to RUN. They stay ON for up to 9 seconds and
then go OFF. They will stay OFF for about 7-15 seconds
then come ON again for about 1 second, than go OFF
again. If you don’t start the engine, the glowplugs should
keep cycling like this, due to the glowplug cycle timer in
the glowplugs controller. It you start the engine, they will
cycle until the engine is warm, due to the afterglow cycle
timer in the glowplug controller. When the engine gets up
to 120 °F (49 °C), the glowplugs should stop cycling
completely.
ENGINE NOT RUNNING
If the glowplugs are cycling property, you should hear a click
from the protective control box (PCB) when the glowplugs
turn on and when they turn off. This is the glowplug cycle
timer, a thermal circuit breaker. A good way to check for
cycling is STE/lCE-R test 80, battery current. When the
glowplugs turn on, STE/lCE-R will measure 74-125 amps.
When the glowplugs turn off, the STE/lCE-R will measure
3-8 amps.
ENGINE RUNNING.
ROTARY SWITCH IN RUN
If the glowplugs are cycling properly, you can hear a click
from the protective control box (PCB) when the glowplugs
turn on and when they turn off (you may have to duck your
head under the dash). This is the afterglow cycle timer, a
thermal circuit breaker. A good way to check for cycling is
STE/ICE-R test 80, battery current. When the glowplugs
turn on, STE/lCE-R will measure 74-125 amps. When the
glowplugs turn off, STE/lCE-R will measure 3-8 amps. As
the engine gets warmer, the glowplugs turn on leas
frequently and for baa time.
NOTE
If you don’t have a STE/lCE-R or a multimeter for measuring
current, you can watch the vehicle volts gauge for indication
of glowplug operation. The glowplugs drew so much current
that the volts gage should jump about half-an-inch to the left
when the glowplugs come on. Before starting the engine, you
should hear the glowplug power relay click open and closed
as the glowplugs cycle. (You can hear the relay after the
engine has started by leaning your head under the dash near
the protective control box.) This method won’t tell you if all
the glowplugs are working property, but it at least shows that
the glowplugs are trying to work and that the glowplug power
relay is working.
TM 9-2320-280-20-1
GLOWPLUGS
2-307
