How do I get to a cracked shower drain in a harmony sunnybrook trailer 21 ft. Mel

Question edited for a lot more clarity.
Question moved from Cars and Trucks.

According to snippets I see here, fibreglass and a rubber coating over aluminium roof trusses.

https://www.google.com/search?q=2004+sunnybrook+titan+roof+materials

..

Not much available on that one :>(

https://www.google.com/search?q=1998+sunnybrook+26%27+travel+trailer+owners+manual

..

Not published anywhere, ask the maker direct, Fixya is not they.

2013 SunnyBrook Raven 2980BH Fifth Wheel Specs

www.sunnybrookrvs.com > specifications-2013-sunnyb...

Your research stops here! Find everything you need to know about the 2013 SunnyBrook Raven 2980BH Fifth Wheel.

2013 SunnyBrook Raven Specs & Floorplans

www.sunnybrookrvs.com > specifications-2013-sunnyb...

View available 2013 SunnyBrook Raven floorplans & specs. ... View Specs & Floorplans 2013 SunnyBrook Raven. Find Specs for ... Find Specs for 2980BH.

Actually, Winnebago now owns SunnyBrook. You will need to contact Winnebago Industries directly. The General number for Towables is (574) 825-5250. Listen to the menus, they may list SunnyBrook as an option. You likely will need Parts Department.

If it were mine I likely would rather than be surprised with a leak that can damage panels and cause the formation of mold often behind and under panels.

It is most likely inside the tank or under the sink.

Sunnybrook was bought out by Winnebago in 2010. They might be able to help if you contact them.
Alternative would be to turn on all 12v items that you can, then pull a fuse and see what's not working. A lot slower than getting a diagram, but it's a learning process.

Look under trailer for red and white capped off lines. My motor home drains are the outside shower valves

If you don't have a hot water heater winterizing bypass kit installed,get one before going any further.
Next, drain the water out of the hot water tank. Add POTABLE (not automotive) anti freeze to the water system Run run faucets one at a time both hot and cold, toilet and shower head until you see the anti freeze . Next, shut off the water pump and open the faucets. This saves any chance of cracked water lines. When you want to use the trailer again, close the bypass valves on the hot eater tank and run the pump long enough to remove the antifreeze solution from the system. Fill the water tank and run the faucets for a few minutes. Potable antifreeze won't make you sick so there's no worry if you don't get it all out of the system.

Is it leaking at a glued connection or a jam nut connection? If at the jam nut connection you may need to replace the jam nut washer to get a good seal. If it is a glued connection. You may get luck and reseal the connection by swabbing some ABS glue over the leaking area. ABS glue is thick black glue and may be found at your local RV dealership.