Seadawg,
And Voila! It's working! Showing all tank levels and battery charge level now. Let's see:
Since the discovery of this problem,
1. I finished mowing the lawn
2. I put out the awning, and turned on the awning and curb lights to aid packing
3. I turned on the LP to start cooling the frig
I checked the SeeLevel. Now I have to figure which one of the above corrected the problem. I'm leaning toward a propane-powered display panel. I'm now not sure if I'm happy it's working, or....
But seriously, I had emptied all three tanks after our last trip a few weeks ago. Are the sensors internal, and at least one needs to sense liquid as a feedback to enable the display? The display was dark after filling fresh water, and was when i checked an hour later. I tried the battery + gray buttons for 5 seconds in case it was a display issue, but got nothing on the display. Next time I'll wait until the next day before asking y’all for help! Unless I smell something burning...