Before working with the propane system, visit the
Gas safety page.
There are two variations of the wiring for the second generation gas systems. Older models like the
RM2607, RM2611, RM2807, and RM2811 came with the old wiring. Most other
models came with the new wiring below. But, it's not that simple. Some of the other models started
out with the old wiring and evolved into the new wiring later on. And, many of the models that
originally came with the old wiring were later updated with a new wire harness when the main
(lower) circuit board was changed. Some of the failures of the main circuit board on the older
models were attributed to the wiring -- thermocouple grounding problems in particular. The new
wire harness didn't fix the bad circuit board, but was supposed to prevent similar failures on
the replacement board. The most obvious difference between the two wirings is where the thermocouple
wires go. On the new wiring, both thermocouple wires go to the circuit board. On the old wiring,
one wire from the thermocouple goes to the circuit board and the other goes to the common ground
When gas is chosen as the heat source (either by the user or by default), the circuit board sends 12 volt
to the gas solenoid and to the igniter through
the yellow wire from the modular plug at the top, right of the circuit board. The gas solenoid opens
and allows gas to go to the burner. The igniter sends high voltage to the electrode which sparks to
the burner and lights the flame. This in turn heats the thermocouple (and
also heats the cooling unit boiler). The thermocouple generates millivolts that are sent back to the
circuit board to let it know that the flame is lit. Knowing the flame is lit, the circuit board allows
it to burn by continuing to provide the gas solenoid and the igniter with 12 volt. The circuit board
will try to light the burner for approximately 45 seconds. If the burner fails to light within that
time, the circuit board will quit sending 12 volt to the gas solenoid and igniter. Also, the check
light on the eyebrow will be illuminated. If the check light comes on, the refrigerator needs to
be turned off and back on before it will attempt to light the burner again.
Gas problems generally fall into three categories. One, the flame doesn't light. Two, the flame lights
but goes out and the check light comes on. Three, the flame lights and stays lit, but the refrigerator doesn't cool.
- If the refrigerator doesn't light when it should, the first thing to do is verify that the
refrigerator works on AC (electric). This lets you know that other critical parts are doing their
job. Turn the temperature control all the way up to insure that cooling is called for. Assuming
everything else is alright, select gas at the eyebrow and check to see if the solenoid and igniter
are attempting to work. Usually you can hear the gas solenoid open, or you can put your finger
on it and feel it when it opens. If the igniter is working, there will be sparking at the burner.
If one or both of these components fail to work, check for 12 volt to them. If there is no power
to one of them, the main circuit board is bad. If 12 volt is present at the component that
isn't working, then there is a problem with that component. For an apparent problem with the
igniter, see the igniter page. With a solenoid problem, test for 12
volt across its two terminals. If 12 volt is present and the valve doesn't open, the solenoid
valve is bad. By checking across the terminals you are insuring that a ground is present. If
everything seems to be working as it should but the flame doesn't light, be sure the propane
is not shut off (including at the refrigerator itself). Also, though very rare, there is a
possibility that the orifice could be plugged.
- In a situation where the flame lights but goes out, the problem is going to lie in the thermocouple
circuit. This would include the thermocouple, the flame, and the circuit board. If the flame is a clean
burning flame, it is probably OK. When heated by the flame, the thermocouple
should produce between 25 and 35 millivolts. This can be measured at the wire connectors at the end
of the thermocouple wires. If you're getting the millivolt readings mentioned and still have the check
light problem, the cause is the circuit board. In fact, the circuit boards on these models are somewhat
notorious for having a problem with the thermocouple circuit, resulting in an erratic check light
problem. We have been replacing these boards with an after market board, the
Dinosaur brand P-711 with very good success. It has a 3 year warranty and
a special thermocouple circuit.
If the gas flame lights but the refrigerator doesn't cool properly, your problem would be in the
flame itself or the cooling unit. Try the refrigerator on AC (120 volt) to eliminate the cooling
unit as a possibility. If it works on AC, the cooling unit is not the problem. That leaves the flame.
A problem with the flame is a basic problem that can affect even the oldest model refrigerator.
See the burner page for tips on fixing a bad flame.
A side note:
Sometimes when traveling the flame goes out, doesn't re-light, and the check light comes on. This
can be caused by the flame drifting away from the thermocouple when the vehicle is in motion.
There is no adjustment for the thermocouple, but the metal bracket holding it can be bent so the
thermocouple is further into the flame.