In my basement compartment there is a cutout approximately 14" x 14" near the back of the UDC that has 4 screws, that when removed, will give access to the water pump for winterizing. To get full access you will need to pull that whole wall down instead of just the cut out. It also has 4 screws with the square head.
My pump stopped working and when I checked it, it was really hot. After it cooled down it started working again, but will occasionally overheat again. I did not see a fuse at the pump on mine, I'm thinking it may have an internal fuse that resets itself. My fuse at the box was also good. Check your wire nuts that connect the 12 volt source to the pump and make sure one has not come loose. Also check your voltage while your there before deciding on a new pump, or taking it to the dealer.
There is a kit available from amazon and other sources that consist of 2 soft water lines that loop to the pump that is supose to assist in quieting the pump, but some just learn to live with it instead.