The electronic igniter (below) changes 12 volt DC power supplied to it by a switch or circuit board into a high voltage spark between the electrode and burner head. There are slight variations of this igniter, the Channel Gaslighter Mark 6, but if you have one that looks relatively similar, you're in the right place. There is also another style a little farther below.
When 12 volt is applied to the "+" and "G" (-) terminals of the igniter, the igniter monitors the resistance between the electrode and the burner. If there is no flame at the burner, the resistance is high and the igniter sends high voltage through the spark wire to the electrode. The high voltage jumps the gap between the electrode and burner and sparking begins. When the flame lights, the resistance between the electrode and burner decreases, the igniter senses this and quits sending high voltage to the electrode. If the flame goes out, the igniter will resume sparking again and usually relight the flame.
When the igniter is sparking, the "L" terminal sends a pulsing high voltage DC signal to whatever it is connected to. The "L" terminal could be connected to an ignition light or to a circuit board.
Troubleshooting. If there is no spark at the burner, first remember that the igniter senses the resistance between the burner and the electrode. If the electrode is cracked (even hairline) or wet, it will ground out and make the igniter "think" the flame is lit, and therefore not spark. The spark wire can also have similar problems. To test for a cracked electrode, disconnect the spark wire from the electrode and set the refrigerator controls to the position where sparking normally occurs. If the wire sparks to a metal part of the refrigerator, the electrode is bad. Before performing this test, however, if an electronic gas valve is involved in the system, locate the manual propane shut off valve at the back of the refrigerator and turn it off so propane is not allowed to flow and accumulate. Also, check the gap between the electrode and the burner. It should be about 3/16".
If the above test doesn't solve the problem, then pull the igniter from the refrigerator. With no other wires attached, apply 12 volt to the "+" and "G" terminals of the igniter, observing correct polarity. If you hear the igniter click internally, it is good. If it doesn't click, the igniter is bad. If the igniter is good, check to see if the refrigerator is supplying correct voltage to it. After that, add the spark wire and electrode one at a time back to the circuit to see if the sparking stops. Turn the igniter off when adding each component, so you don't get a shock.
If you suspect there is a problem with the signal put out by the "L" terminal, it can be tested as in the graphic below. Provide 12 volt to the "+" and "G" terminals of the igniter. Put a neon style AC tester across the "L" and "G" terminals. The tester should flash everytime the igniter clicks or sparks.
You can also test the "L" terminal with a multimeter. Set the meter to 20 volts DC or lower and put the probes on the "L" and "G" terminals, then provide 12 volts to the "+" and "G" terminals of the igniter. The meter should read a pulsating voltage.
There are 25 mA and 50 mA igniters. Do not use a 25 mA igniter in place of a 50 mA one. A 50 mA igniter can be used as a replacement for either. The mA should be written on the igniter.
Tip. With a little customizing and ingenuity, an electronic igniter can be added to a refrigerator that didn't originally have one. The hardest part is mounting the electrode. As for the igniter, ignore the "L" terminal and supply correct power (preferably through a switch) to the igniter. You will also have to tie the wire from the "G" terminal to the refrigerator chassis ground, as well as to the negative side of of the 12 volt DC, to create a circuit for the high voltage. There are two advantages to adding the electronic igniter: 1) convenience, and 2) if you have a problem with the flame blowing out, this will virtually eliminate it by immediately relighting the burner. This igniter is also sold as an after market kit with an electrode, wire, and some mounting hardware.
Another style igniter, one that preceded the one above in RV refrigerators, is the White-Rogers style below.
This style of igniter also came in a few variations, but what makes them all different from the Gaslighter Mark 6 igniter covered at the beginning of this page, is that there is no "L" terminal and there is a separate ground connection for the high voltage side. You can follow the same troubleshooting procedures for the Mark 6, if you suspect a problem with the White-Rogers. The White-Rogers style igniter is difficult to find these days, but you can use the Gaslighter Mark 6 in its place. To use the Mark 6, wire it according to the Tip instructions above.