TRC Surge Guard products are all 'one and done.' If it doesn't fail in the first year, you're on your own. I'd suggest replacing the unit with a good auto transfer switch and then install a Progressive Industries EMS. They have a lifetime repair/replace warranty and are great folks to work with.
You might find a compatible ATS with your Silverleaf or Intellitec systems, or relocate the sensors that provide the information to them.
Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI