broken grey tank valve

During freezing weather I attempted to dump the tanks. The black tank was ok, but when I pulled on the shower grey tank the something broke and I could pull the cable all the way out if I wanted to. Question is, is it very hard to get to that particular valve and repair it?

The valve will be hidden under the under belly cover. You might want to use a 3/8 socket bit on a drill and undo a few screws to see the valve. It will possibly be under the lower part under the shower area. The valve is close to the tank. The cable/adapter might have uncrewed from the valve stem if you are lucky.