Note: The following process is intended to only apply to the 297RSTS with design similar to my 2018 model. While the principles may apply to other trailer models, the author makes no such recommendations. The following information is simply one possible way to accomplish this task.
One of the major challenges with installing solar or a roof-top satellite dish is how to run the additional wiring from the roof to the floor. My solution, for the 297RSTS, was to route the wires behind the hutch along the same path as one of the holding tank vents. By removing the Convenience Center from the hutch side-wall and the lower hutch front panel, I was able to see the path that the floor-to- ceiling wiring used behind the hutch. I sacrificed the upper-right section of the hutch for wiring access and also equipment mounting as seen in the photos above. By (very carefully) removing the wall material behind the upper hutch, I was able to run wires from floor to ceiling (and then through the roof for the solar panel and SAT antenna) along with the factory ceiling wiring. Use extreme caution when cutting away the wall material because the vent pipes and wiring are located directly behind the material. I used a construction razor knife to carefully cut the material no deeper than the thickness of the plywood. Once wiring is routed to the lower hutch area, you can follow existing wiring through the floor to the area between the frame rails. From there, you can follow existing wiring along the inside frame rail to the pass-thru storage area for access to the batteries and main DC wiring. In order to avoid pulling all of the belly cover away from the frame, I was able to use one of the colored satellite coax cables as a pull-wire because I needed to re-route the coax to the upper hutch anyway to connect to the roof-mounted satellite antenna. Even if you do not intend to relocate any of the existing wiring, it's pretty easy to "borrow" one of the colored coax cables, use it as a pull-wire to route a new pull-wire, and then restore the original coax cable routing along with your new wiring.
In order to install the roof mounted solar and SAT antenna wiring, I needed to open a chase from the floor to the roof. The OEM ceiling wiring was routed behind the hutch, but was mostly covered over. I sacrificed the top right bay and boxed it in for wiring access, and also to house some of the SAT antenna, solar, inverter, and EMS components. Looking at the convenience center panel, there is an additional (for the 297TSTS) rocker switch labeled BATT OFF. I replaced the mechanical battery disconnect switch in the pass-thru with a remote operated relay that I control from this switch. This switch and relay are shown on sheet 1 of the Mod Wiring diagram. Click on the individual pictures below for an enlarged view or scan through the gallery.
View into hutch from the top, right, front-facing door opening. The floor to ceiling wiring chase is visible along the back wall. The DirecTV insertion power supply and power outlet, a relay and wiring for the water pump control, and a 12 VDC fuse panel for unswitched battery power are mounted on the gray panel. The rear solar monitor panel, EMS display, inverter remote ON/OFF panelare shown on the right side of the photo. The DirecTV satellite antenna control unit shown bottom-left.
View of the hutch from the side-facing door opening. The solar monitor panel, Battery Charger remote display, EMS display, and inverter remote ON/OFF panel are shown. The door was removed to provide easy access.
The solar control/monitor panel provides advanced battery monitoring, including battery state-of-charge condition in amp-hours from full charge and percentage of charge.
Convenience Center panel as installed by Grand Design. Modifications include the addition of a battery master switch that controls a remotely mounted battery disconnect relay, which replaces the mechanical battery disconnect originally mounted in the pass-thru. The water pump switch was replaced with a momentary push-push switch with 3-point control (Convenience Center, Bathroom, and Pass-Thru), and some behind the panel wiring changes to provide better system isolation.