Glow Plug Testing - Westerbeke 8.0KW-60Hz Service Manual

GLOW PLUG TESTING
GLOW PLUGS
The glow plugs are wired through the preheat solenoid.
When PREHEAT is pressed at the control panel this solenoid
should "click" on and the glow plug should begin to get hot.
a. To inspect the plug, remove the electrical terminal con-
nections, then unscrew or unclamp each plug from the
cylinder head. Thoroughly clean each plug's tip and
threads with a soft brush and cleaning solution to remove
all the carbon and oil deposits. While cleaning, examine
the tip for wear and bum erosion;
if
it has eroded too
much, replace the plug.
b. An accurate way to test glow plugs is with an ohmmeter.
Touch one prod to the glow plug's wire connection, and
the other to the body of the glow plug, as shown. A good
glow plug
will
have a 0.4 - 0.6 ohm resistance. This
method can be used with the plug in or out of the engine.
You can also use an ammeter to test the power drain (5 -
6 amps per plug).
A
WARNING:
These glow plugs will become very hot
to
the touch. Be careful not
to
burn your fingers when
testing the plugs.
c. Re-install the plugs in the engine and test them again.
The plugs should get very hot (at the terminal end) within
7 to 15 seconds. If the plugs don't heal up quickly, check
for a short circuit. When reinstalling the glow plugs, use
anti-seize compound on the threads.
A
WARNING:
00 not keep
a
glow plug on for more
than 30 seconds.
GLOW PLUG TIGHTENING TORQUE 7 - 11 ft-Ib (1.0 - 1.5 m-kg)
TESTING A GLOW PLUG
WITH AN OHMMETER
TESTING A GLOW PLUG
USING A -TEST LIGHT
\ I I
,
TERMINAL
END
TIP
+
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