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SECTION 5 DC COMPONENTS
5.1 Thermistor
Disconnect the thermistor harness from the P2, 2-pin ter-
minal on the lower circuit board. Place the thermistor in
a glass of ice water (more ice than water), approximately
33° F to 35° F. Wait 8 to 10 minutes. You should get a
reading of approximately 8,000 to 10,000 ohms. Always
test from the wire side as shown below as not to create a
connection problem at the P2 connector.
NOTE: The RM1350 will not run constantly when the
thermistor is unplugged or becomes an open circuit, be-
cause the RM1350 has a water tank in the refrigerator
to provide chilled water for the dispenser. Failure of the
thermistor will cause the unit to stop cooling.
5.2 Solenoid
Check the solenoid coil with a properly calibrated Ohm
meter. Remove the connectors from the solenoid and
measure the resistance across the terminals and to chas-
sis ground. The proper reading would be 49 ohms with a
tolerance range of ten percent. Failure of the solenoid is
very unlikely.
Thermistor
unplugged
from PC board
5.3 Igniter
The igniter used on Dometic model refrigerators operates
on 12 volts DC. During gas operation the igniter senses
the resistance through the ame between the electrode
and burner. When there is no ame at the burner, the re-
sistance is high and the igniter begins sparking to light the
burner. As soon as the ame is lit, the resistance between
the electrode and burner drops and the igniter stops
sparking. The resistance is monitored by the igniter, and,
if for any reason the ame goes out, the igniter begins
sparking until the burner is lit. The resistance between the
electrode and burner drops and the igniter stops sparking.
This is an energized circuit. Shock can occur
if not tested properly. Testing is to be done
by a qualied service technician.
This insures that the ame will always be lit when de-
sired. First verify proper voltage at the positive (Yellow
+) and ground (Black –) terminals of the igniter. The read-
ing should be within 1.5 volts of incoming voltage at the
main terminal block during trial-for-ignition. Next, remove
the high voltage cable from the igniter. The igniter should
produce a sparking sound, during trial-for-ignition. If not,
replace the igniter. While operating in the gas mode, the
power module and igniter are constantly monitoring the
presence of ame. If the ame is blown out, the igniter
will immediately start sparking. When the power module
senses the loss of ame (thermocouple voltage below 13
MVDC), the 45 seconds trial for ignition period is started.
The igniter installed on the refrigerators as original equip-
ment is part number 2931132019 (RV Gas Model 679).
This igniter is rated 50 MA. This igniter may also be used
on any other model. When replacing the igniter, always
provide the product number for proper replacement. DO
NOT install the Channel Mark 6, Model 12 E igniter (as
shown) as a service replacement part. Installation of the
Channel Products, Inc., Gasliter Mark 6, Model 12 E, will
VOID the warranty on the refrigerator. The Dometic re-
frigerator could use a few different igniters. To acquire the
proper igniter always provide the product number from
the unit you are working on.
Next, hook up a manometer at the test port. Then check
for DC volts at gas valve terminals (Yellow + White -)
while the unit is in trial-for-ignition. If DC volts are present
and pressure is low, replace the valve. If DC volts are not
present at the valve while the unit is in trial-for-ignition,
verify that the wires at Plug 3, Terminals 2 and 1 (on lower
circuit board) have DC volts (9 or more). If the igniter is
sparking and you have no volts at the valve, check the
harness. The control board sends voltage to the solenoid
and the igniter on the same wire.
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