Very nice red diesel tractor and great family pics!! Some of the cheaper ones are nothing but junk from afar. Sounds about right, they last long enough and then die out. I'm with Uncle Lewy......are all of your switches from the same brand/company?
NOTE: For your grandchildrens' safety, you should see about putting a belt cover on that deck, though.
Don't know if you have already seen this or not, but perhaps this might help:
http://www.onlycubcadets.net/forum/showthread.php?t=21
Cub Cadet 123