5
DIAGNOSTIC SERVICE MANUAL
Dometic
®
RM2604/2804
Refrigerators
To check the high voltage cable, first disconnect DC
power at the igniter, lamp terminal block. Next, discon-
nect high voltage cable from electrode. Then reconnect
DC power to the terminal block. If sparking starts, cable
is good, DO NOT REPLACE, check the electrode (See
Sec 4.3). If no sparking, disconnect DC power at the
igniter, lamp terminal block and then disconnect high
voltage cable at the igniter. Reconnect DC power to the
terminal block. If sparking sound from igniter, replace the
high voltage cable.
4.5 DOOR SWITCH
The door switch is an open switch when the switch arm
is depressed (interior light should be off). When the
refrigerator door is open, the switch is closed (interior
light should be on). Check that the switch assembly is
properly aligned and that it is not broken. Check the
switch assembly for continuity. When the switch arm is
depressed there should not be continuity. When the
switch arm is NOT depressed there should be continuity.
If any of the checks are incorrect, replace the switch.
4.6 RELAY (3-WAY MODELS ONLY)
The relay controls the circuit to the DC heating element.
The load (amps) of the DC heating element goes
through the relay.
To check the relay, first verify the
selector switch is on DC mode
(See Sec. 4.1) and the
thermostat (See Sec. 2.2) is
NOT completing the circuit.
Next, verify voltage is present
between terminals 85 and 30. If
voltage is not present, check
wiring to both terminals. (See
Sec. 7.2)
Next, check for voltage
between terminals 85 and 87.
If voltage is present, the relay
is defective and needs to be
replaced.
Second, verify the selector switch is
on DC mode (See Sec. 4.1) and the
thermostat (See Sec. 2.2) is completing the circuit.
Next, verify voltage is present
between terminals 85 and 86.
If no voltage is present, check
wiring and connections (See
Sec. 7.2).
Next, if voltage is present,
between 85 and 86 terminals,
then voltage should be present
85
30
87
85
86
PRESSURE T EST HOUSING
87
between terminals 85 and 87. If no voltage is present,
the relay is defective, replace it.
4.7
HEATING ELEMENT
(3-WAY MODELS ONLY)
The heating element is designed to deliver a predeter-
mined amount of heat to the cooling unit. Check the
heating element with ohms resistance using a properly
calibrated ohm meter. This check is to be done with the
element at room temperature. The proper ohms for
RM2604 and RM2804 DC heating element is .67 with a
tolerance range of ten (10) percent. If the heating
element is outside the
tolerance range, replace it.
NOTE: It will take a very
precise ohm meter to
accurately read this
measurement. If a precise
ohm meter is not available,
a continuity reading will
indicate an open or com-
plete circuit. If an open
circuit is the test result,
replace the element.
SECTION 5
LP GAS REQUIREMENTS
The LP gas pressure to the refrigerator should be 11
inches water column with half of all BTU’s of the RV
turned on. With all other appliances turned off, the
pressure to the refrigerator should not exceed 12 inches
water column. To check the gas pressure when the
refrigerator is operating, there is a pressure test housing
located just prior to the orifice.
85
85
