It's a problem replacing one of the Winegard automatic antennas. I was able to find a refurb unit but Winegard is not selling any any longer. If that was a factory installed option you should contact the manufacturer to see if they have any replacements available. Winegard did provide the manufacturers with that product for awhile after they stopped selling to the public.
If that does not work I would recommend having the manual Sensar IV antenna installed as a replacement. You are likely going to have to relocate the antenna when you have clear ceiling space to drill a hole through the roof and through your ceiling into the coach. However, you will be able to reuse the existing coax running from the roof into the RV by simply making an extension that you can run from the new antenna, across the roof and a barrel connector to put the 2 pieces together. Use some caulk drops every couple of feet to hold the coax firmly to the roof and it will last for years and years.