Dometic RM1350 - Fuses; DC Water Dispenser Valve

23
Lower Board Testing
NOTE: All tests are to be done with refrigerator on and
in the cooling mode. Place the thermistor in a glass of
warm water (75 to 80 degrees F.) to assure the unit is
calling for cooling.
DC Volts
Measure volts between terminal J1 positive and J10
ground. Voltage should be the same as at the positive (+)
and negative (–) on DC input terminal block. The operat-
ing range is 9.6 min to 22 max. Refer to wiring diagram on
the product number unit you are currently working on. If
voltage outside the 9.6 to 22, check power supply, termi-
nal block, thermofuse and correct power source before
going on with the test.
AC Mode
Before testing the lower board for AC operation, test upper
control panel ON/OFF switches, LED display control and
wiring harness between upper and lower controls. Next
check that incoming AC voltage is present at terminals J5
(black) and J6 (white) on the circuit board. With unit in AC
mode, check for voltage at the heating element connec-
tion terminals J7 and J8 on the circuit board. If no voltage
is present and 5 amp AC fuse, 3 amp DC fuse, wiring har-
ness and upper controls test ok, change the lower control
board. The AC voltage detection circuit is damaged.
This is an energized circuit. Shock can occur
if not tested properly. Testing is to be done
by a qualied service technician.
Gas Mode
Note: The Dometic control board used in the
RM1350 is a 3 try system in the gas mode.
There is a 2 minute purge cycle between
each 45 sec. trial for ignition. Flame failure
could take 6 to 7 min utes.
Verify that the following components are good: upper con-
trol panel ON/OFF switches, LED display control and wir-
ing harness between upper and lower controls and 3-amp
DC fuse. First, check for voltage during trial-for-ignition
(45 sec.) at Plug 3, Terminals 1 (white wire negative) and
terminal 2 (yellow wire positive) to the igniter and solenoid.
If no voltage is present change the circuit board. If voltage
is present, check for volt age at the igniter and solenoid. If
no voltage is present, check the wires from P3. To check
the ame sense circuit of the lower circuit board, operate
the refrigerator on GAS and measure the millivolts be-
tween J4 (NEGATIVE) terminal and J10 (POSITIVE) con-
nection from the thermocouple. The thermocouple should
produce 20 millivolts DC minimum. Anything less than
20 millivolts will cause erratic gas op eration. The meter
should read between 25 to 35 millivolts with the gas ame
burning. When the power module senses the loss of ame
(thermocouple millivolts below 13 MVDC) the 45 seconds
trial for ignition period is started. A brief interruption of DC
power (loose positive or negative wire) may cause check
LP to come on. A brief interruption of DC power (loose
positive or negative wire) may cause check LP to come
on.
Erratic/no gas operation tips
1. Apply straight line voltage to unit from a battery.
This will eliminate any problems with converter voltage,
bad grounds at the converter and other components on
the same DC line.
2. Unplug the coach from shore power.
Other components in the coach can send out RF that
might interfere with operation.
12 Volt Valve
Water in Door
120 Volt Valve
Icemaker
5.14 DC Water Dispenser Valve
5.13 Fuses
The main control board has two fuses. The 3 amp DC
fuse is designed to protect the circuit board from internal/
external DC shorts. The 5 amp AC fuse is designed to
protect the integrity of the AC detection and heater circuit
from shorts. There is also a wire with a 4 amp fuse from
the terminal block to an external relay for the fans and
water line heater. All fuses can be checked for continuity.
If a fuse blows don’t replace it until the problem has been
found. If a fuse blows there is a short or component that
has created the problem.
This valve is solenoid operated. When it is open, it releas-
es water from the source to the dispenser. The amount of
water is proportional to the length of time the water valve
switch is held closed by the lever. Disconnect power to
the appliance, remove the wires to the water valve sole-
noid coil, and check for continuity between the two termi-
nals. The Ohms value should be 14.4 +/- 10%. If you have
continuity, normally the solenoid is good. The valve has a
ow washer inside which acts as a pressure regulator. A
strainer is installed to prevent dirt, rust, etc, from entering
the valve. Check for any debris which might obstruct the
ow of water, or prevent the valve from closing completely
when the circuit is not energized. Remove any obstruc-
tions. If the valve still fails to operate properly, replace it.
If the valve has been cracked from freezing this would not
be a warranty item.
NOTE: The fail safes of the gas system are active all the
time the unit is on. If the unit is operating on AC and de-
tects a problem on the gas side the E1 error code or the
LP ashing in the display can come up. The unit will still
be operating on AC but gas operation will not be allowed
until turned off and back on.