4-108. DIESEL GLOW PLUG SYSTEM MAINTENANCE. (Continued)
If the engine is cranked during or after the
above sequence, the glow plugs will cycle
ON/OFF for a total duration of 25 seconds
after the engine control switch is returned
from the crank position, whether the engine
starts or not. The engine does not have to be
running to terminate the glow plug cycling.
All the times mentioned previously are
approximate because they vary with
initial engine temperature. The initial
ON time and cycling ON/OFF times
vary also with system voltage and/or
cause longer duration of cycling.
Do not manually bypass the relay in the
(1) Remove the connector from the inhibit
glow plug controller (2) if jump started
switch when the engine temperature is
with more than a 12-volt system. The
below 100° (38° ).
glow plugs could be damaged.
(2) Set the ohmmeter on a low range or use
a self-powered test lamp.
The glow plug inhibit switch is
(3) Test across the terminals.
temperature controlled and opens
above 1250F (51. 50C) to prevent flow
(4) The switch should be closed (test lamp on
plug operation above this temperature.
or a reading of less than 0.1 ohm on the
It is mounted at the rear of the right
(5) Test terminals to ground with a test lamp
c. Check the temperature-controlled switch to
or the ohmmeter on a high range. The
make sure it is closed at low temperatures and
lamp should be off or the meter show
open at high temperatures.
greater than 1.0 megohm.