I know this is an old post but thought I would add some options for future installers. I just installed the same Isolator in my 2018 R23. I noticed the same things regarding the lack of slack in the wiring when I was planning to pull the shore power plug. I followed the wires down and found they came into the Port battery storage area and then behind the outer wall as they run forward. I laid my old self down on my belly and stuck my head in the battery area and looked to the rear. I could see the wire harness near the top rear of the box. Not easily accessible. Then I exhaled and looked again. I noticed it was looped back about a foot and zip-tied to itself. I thought to myself, did RT leave extra wire so the plug could be pulled out easily. Yep, after cutting the zip-tie I had enough wire to reach all the way to the middle of the starter battery.
I chose to place the Isolator on the divider panel between the battery area and the center hatch, since my Tug has the Generator under the center hatch. After careful consideration I found a spot next to the starter battery since it sits front to back and not side to side like the house batteries. To prevent damaging fuel and water lines, I was able to hold the Isolator against the wall of the center compartment and mark the top holes with a sharpie. Then I moved the isolator and used a small cordless drill with a 3/32 drill bit. I drilled all the way through the approximately 1/2 in thick divider panel. Then I held the Isolator up and put two sheet metal type screws in the top holes. Then I marked the bottom two holes and drilled them.
Since the divider walls appear to made of a composite material (plastic?) my options were to bolt through with lock nuts or four SS sheet metal screws. I opted for the sheet metal screws but added a strip of extreme double-sided tape to the isolator between the top two screws and the same on the bottom. Wipe divider clean and then peel back the plastic on the double= sided tape a little. I started the screws and then peeled the plastic off the double-sided tape and pushed the Isolator against the wall. It felt solid and the tape will give a little cushion for vibrations. The unit frame does not need to be grounded. Tighten the screws and they do not stick through the divider.
Pull the wire loom over and carefully slit open the sleeve. Find the green wire and cut it so one end can reach the rear of the Isolator terminal. It is a 10 gauge wire so I used a 10 gauge medium eye crimp-able wire connector. I did not have a bare connector so I twisted the plastic cover off of the crimp end. I slide some green shrink wrap down the wire, crimped the end on and added a touch of solder. Slid the wrap up over the crimp and heated it to shrink tight. I attached that end to the rear Isolator connector and then added about ten inches of wire to the end of the cut green wire. Crimp, solder and wrap as before and then connect to the forward terminal. Tape the loom sleeve back up and zip-tie away from sharp items. Plug into shore power and test. All working just fine.
Only draw back is if I ever need to pull the shore power plug lose, I will need to disconnect the Isolator to get enough slack to get the plug out to service. I doubt I will ever need to do that. What works for me may might not work for you. I offer as another possible option.
