Welcome IslandTime. You have an Airstream similar to mine, but newer. Owning an Airstream involves a lot of "projects".
Well, I just started a new thread "Fresh water leak from hell". That's exactly the way I feel about the puddle under my Airstream. Our Airstreams are alike in that regard too.
First, there is an access panel on the fresh water pan below the drain valve connections. I used this access panel to replace my fresh water drain valve. On my 86 Limited, there is a 1 1/4 big drain plug (not leaking), and two 1/2" pipe thread spin weld fittings. One is for the drain valve, and one is for the inlet to the 12v
pump. Your can see them. Neither were leaking on my trailer.
Possibly in the wardrobe or galley, you will find a small hole in the subfloor with three gray plastic tubing lines. My leak is coming from one of these three lines. I can't see it, or certainly can't fix any leak in this area. I'm perplexed right now.
The fresh water tank is surrounded by a big metal pan that is bolted to the frame. The fill hose and tank vent line come out of the top of the tank. The 12v
pump "draw pipe" is located on the bottom of the tank. Removing this tank located between the axles would be a nightmare. I may have to do it to fix my leak.
First, find the source of your dripping. Think about these tests:
1. Pressurize your system with city water without any water in the fresh water tank. Run water in the galley and bath faucets until the air is bled out, then stop. Keep the pressure on and come back in an hour. It is leaking? Mine is.
2. Disconnect city water, fill your fresh water tank. Do not pressurize anything. Faucets open, no water coming out, no pressure in the lines. Come back in an hour. Is it leaking? Mine was not, so it ain't the fresh water tank or it's lower connections.
3. Now pressurize your system with the 12v
pump. Run water in the galley and bath faucets to bleed the air, then stop. Keep the pump "on'. Come back in an hour. Is it leaking? Mine is.
Hope this helps. Working together we may figure out where this leak is coming from.