Refrigerator only works on shore power?

1. There is NO pilot light. That is the regular flame
2. Yes, it could run 2 to 4 minutes if the Thermocoupler was bad, but that is rare. MOST flame sensors shut down after 45 seconds, UNLESS you are not watching and the refer does a triple start. Most refers have a tri start ignition cycle that will light, then shut down after 45 seconds, the wait a few seconds and relight and if it shuts down will wait a few seconds and then try the 3rd time. If no flame sense after the 3rd try it locks out and the check light comes on. THAT can be your 2 to 4 minutes. IF that is not the case, then a flame thermosensor can have an intermittant operation and then shuts off randomly.
3. NO FUSE will cause this problem. It is either the Flame sensor or the main control board. 9 time out of 10 it is the flame sensor, unless you have a Dometic refer built from about 1992 to 1998. Doug

CaptRick wrote:
If the thermocouple were bad would the pilot still light and run for 2-4 minutes?

Thanks

Yes.

Batteries and propane tanks are good. There is no air in system as the refrigerator burner starts and runs with a good blue flame for 2-4 minutes before it shuts down.
If the thermocouple were bad would the pilot still light and run for 2-4 minutes?

Thanks

The flame detector (thermocouple) may be defective.

I always burn the stove top burners to purge the propane lines real good before switching in the fridge...

If the black box is working ok with shore power then that would tell me the DC requirements for the black box was good. Perhaps your batteries are disconnected or not working correctly.

Just a couple of my thoughts
Roy Ken