For reference on the wiring... Most importantly, disconnect all power 110vac and 12vdc before starting.
The actual strip goes inside the rooftop unit. You have to remove the cover (4 screws IIRC) and remove the styrofoam insulator. The strip simply slides in and attaches with included screws into predrilled holes. Rather easy. Dangle the strips power cord down through the roof opening and reassemble the foam and ac unit cover.
Inside the rv remove the filter cover and you will see your strip power cable dangling and the old brain box (I am sure it has a better name but that is what I will call it). There will be four sets of wires going into it. A normal three strand 110 wire (hot, neutral, and ground) attached by wire nuts, a squarish cannon plug that is the connection to the rooftop unit, a plug that looks like a phone jack which is the thermostat connection, and a small gauge two wire lead going to the furnace. The two furnace wires are low voltage and trigger the furnace (it will have its own 12v wiring going to it). The new box will have a fifth plug in for the heatstrip. The plugs are all different shapes so it is pretty idiot proof. Word of caution, the old brain box was plastic and held in place by a half threaded wood screw. The new box is made of sheet metal and I replaced the goofy (overly long) wood screw with a short sheet metal screw utilizing the same predrilled attachment holes. That screw somehow came into contact exactly with the hot 110v input and shorted out the minute I put power to it. I removed the screws and used double sided 3m automotive trim tape to secure the brain box to the ac unit.
The thermostat is wired in with three small set screws. Take a picture with a smartphone so you don't forget which color wire goes to which screw.
Hth. Minus the Sparks and removal of offending screws, the install took less than an hour. If you choose to put strips in both ac units, you will need two new thermostats with two new brain boxes. If you have any more questions let me know.
2015 puma 295bhss
2009 ram 3500 6.7l ctd