4-108. DIESEL GLOW PLUG SYSTEM MAINTENANCE. (Continued)
(6) Replace the temperature control switch if
it tests open across the terminals or if
(3) If the plugs do not turn on, disconnect the
either terminal is closed to ground.
controller connector, and check the
connector harness terminal B with a
(7) Disconnect the plug from the switch
grounded 12-volt test light. The light
terminals when the engine is above
should be off with the engine control
125° (52° ).
switch in RUN, and on when the engine is
(8) Set the ohmmneter on the highest scale
or use a self-powered test light.
(4) If the light does not operate as described,
repair a short or open in the engine
(9) Test across the terminals.
harness purple wire.
(10) Test from each terminal to ground.
If the light operates, but the afterstart
glow plug feature does not, replace the
(11) Switch should be open (test light off or
diesel glow plug controller.
high ohm reading of greater than 1. 0
megohm on the meter).
Glow Plug Afterstart.
Install the glow plug (1) and torque to 12 ft-lbs
The glow plug controller provides glow plug
operation after starting a cold engine. This
after-start operation is initiated when the
Connect the wire connector to the glow plug.
engine control switch is returned to "RUN"
from the "START" position. While loss of this
function may not cause a cold start complaint,
it may result in excessive white smoking
and/or poor idle quality after start. To check
for proper operation of this circuit proceed as
(1) With the engine cold 80° (27° ), turn
the engine control switch to the RUN
position and allow the glow plugs cycle.
(2) After 2 minutes crank the engine for 1
second. (It is not important that the
engine starts). Return the engine control
switch to RUN. Glow plugs should cycle