I have a 2006 Sundance maxxus 880, My stereo quit working. I tested all fuses to include ones behind stereo. I have no power coming to the stereo fuses. I see the wires run down to a black box behind the main electrical panel which looks very tough to get to. I was wondering if that’s were I need to get to or if there is something in the main electric box I need to look at? I also have pushed the reset button on the deck still no good. Thank you