If the engine cranks ok (or starts), then the batteries are
good enough for testing the glow plugs. If the engine
starts, shut it off.
You can use STEXE
Test 10 to measure cranking speed.
The engine should crank at least 100 rpm in cold weather
and at least 180 rpm in warm weather.
GLOW PLUGS CIRCUIT
The WAIT-TO-START lamp is NOT
diagnosed in this section. If the lamp
does not work properly, the glow plug
circuit may be affecting Its operation.
Run these tests to check out the glow
plug circuit. If the lamp still does not work
properly, go to the INSTRUMENT section
for a full diagnosis of the lamps problem.
Disconnect negative battery
cable before disconnecting and
reconnecting PCB harness.
There is battery voltage at the
PCB at all times. Failure to
disconnect battery cable will
result in damage to equipment
or injury to Personnel.
ARE THF MOST COMMON
Sometimes just disconnecting,
reconnecting will solve a problem.
The time you save may be your own. Refer to the
functional flow schematic and check the following:
- make sure all connections are clean and
tight. including the shunt and power stud.
CQNTROL BOX - remove BOTH
connectors and look for bent or broken pins, pins
pushed out of their socket. or dirt and corrosion in the
3. GLOW PLUG CONTROLLER
- pop the controller
connector off (squeeze the sides) and check the pins in
both the controller and the connector.
Look for bent.
broken or pushed out pins, die, or corrosion.
broken wires at the connector.
Take note that pin 2 of
the glow plugs controller connector has no pin in it.
4. GLOW PLUGS - check that all the glow plug wires are
snug. Dont just look with your eyes. Many problems
are solved by looking with your fingers to be sure a
connection is snug.
GLOW PLUG OPERATION
The glow plugs first come ON when the engine temperature
is below 120 F (49°C) and the rotary switch is turned lo
RUN. They stay ON for up to 9 seconds and then go OFF.
They will stay OFF for about 7-15 sewnds then come ON
again for about 1 second.
1. Set the voltmeter to a DC volts scale of about
2. Connect the BLACK lead to the battery side of
the current shunt and the RED lead to the
other end of the current shunt.
3. Current shunt voltage is proportional lo battery
current, 100 millivolts = 1,000 amps. To get
current, multiply millivolts x 10.
STEIICE-R TEST 80
To check for glow plug current
draw, start STE/lCE-R Test 80, Battery Current. Turn off all
accessories (lights, heater, wipers, etc.). STE/ICE-R should immediately measure at least
74 amps. Take note, however, that if all your glow plugs are working,
the current draw
should be close to or more than 100 amps, especially if its cold. If its near freezing and
the glow plugs only draw 75-60 amps, you probably
have a few bad glow plugs.