I see 2-3 things that I would guess might be the problem and I would want to check them as a first step. One could jump to saying the sensing board in the power center is bad but that is not the first move I want to make until I look further as it can also be the connections to that board are not good and those are a whole lot cheaper/quicker to fix!
So a look at the drawing here is needed but I was not able to say exactly which page as there are different options on different Rv that change which page but for this purpose, I think you can depend on either sheet 3 or 4 if you are not able to sort which options you have:
https://www.winnebago.com/Files/File...ire_171004.pdf
I did these snips of the drawing and highlighted the things I would first want to verify, looking for loose, corroded or damaged wiring of all the connections but especially those I have marked. Use care to verify there is no power before going further but I would check all the connections in these two for tightness, etc. Click these for better view but load center is on left and transfer switch on right. I would look especially at the grounding of the wire through the sensor as if it is not well grounded, it may be picking up some form of induction to be sensed as power being there.
Next step might be to say the module is bad????
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Richard
Why no RV year, make and floorplan on MY signature as we suggest for others?
I currently DO NOT have one!