As I recall: the tank filler is on the passenger side behind the coach door...
limber up, and take a peek under your coach there. You should see the tank...
Follow the lines until you either see the pump; or you see where they disappear into the coach. That should give you enough info to find it.
Good luck, and happy hunting!
Good Sam Member 843599689
Current coach: Tiffin Wayfarer 24 BW
"History shows again and again; how Nature points out the folly of Man!"