KayChuck.......I'm not familiar with the Blue Ox Patriot, but if it's drawing power from the Buick to operate, you may want to do a couple of things. First, your motor home trailer plug has a 12 volt power lead. If you add a wire to your toad connector cable and then connect it to your Buick battery, it will keep your battery charged. If you do it this way, you need to add a fuse in the wiring to keep the system from shorting out. There are a couple of companies that make a kit for this, one of them being "Toad Charge", but I found their product, especially the connector ends kind of cheesy.
Second, I think the simplest way to solve your power supply issue from the Buick is to run the direct line from the battery with a heavy duty fuse or circuit breaker into an auxiliary cigarette lighter plug.
Don & Mary
2014 Newmar Dutch Star - All Electric - 450 ISL
2016 GMC Canyon 4WD Crew Cab