I have Garmin RV760LMT. 9,000 mile trip last summer, 4,000+ mile this summer. works fine. Had issue in NY state where gave me strange routing. Set intermediary points. Still routing strangely. Used Google Earth and found out low RR bridge it would route me around. Did its job. Another routed me around a bridge with low weight restrictions under RV weight. Another around a low clearance tunnel. Gives MPH posed for road and MPH traveling. Can set Miles and KM for travels into Canada.
Each site is different with rocks, trees, etc in site and across from site. There is a web site that gives pictures of each site. ?worth looking at them. Sometimes you can overhang beyond end of site; others there is a tree or rock preventing that. Some sites have free access across from site allowing truck maneuvering while backing; others have tree right across preventing the truck from maneuvering while backing. Really a mixed bag there.
ditto on the charge line. You most likely have an unused wire in your umbilical cord and a charged pin on the MH connector. Just pick that up in the car connector and run a #10 or 12 wire from connector to battery positive post and put an in line fuse.