That silver part with heavier wire is the AC element that lets you use it when you have 120VAC shore tie or generator or inverter power.
Get your Norcold Model Number and go to
Chris Bryant's Site and select Service Manuals. Download a manual, study the troubleshooting and see what it yields.
To run, a fridge has to "prove flame" and that can be done with a Thermocouple or a Flame Sensor. I think you have a Flame Sensor.
If it gets lit and flame is not "proven" then the fridge shuts the gas off and tries a couple more times. After that, you have to shut it off at the controls and turn it back on again to get another set of tries.
What concerns me is that the valve must be opening because you have gas that you can light manually, but the spark electrode cannot. That's peculiar. Sounds like there could be multiple problems.
Make sure the "electrode" is clean and that its tip is in the flame. I think it's both Igniter and Flame Sensor.
If God's Your Co-Pilot Move Over, jd
2003 Jayco Escapade 31A on 2002 Ford E450 V10 4R100 218" WB