Thanks for the reply... Its ironic that you were the one who answered my post, because I saved a photo that someone posted on Facebook of your coach with the Mini Split AC Units mounted to the back bumper.
Im also looking to do the same thing, only one Mini Split though (I think)... Maybe you could answer a couple questions regarding your installation:
1) With the mini splits mounted above the bumper and the spare behind them, do you think it would interfere with towing a open car trailer?
2) Do you have any drawings of the mounting brackets you made to mount the AC Units and the spare tire? Or photos?
3) Where did you mount the inside units? And how did you route the electrical wiring and drains?
Im thinking of making a bracket that attaches to both rear cabinets above the bed and centers the inside unit so it points down the hallway of the motorhome... Ive seen a few others do it this way....
Thanks for responding to my posts...
Steve
Steve:
Kendra got back to you before I could. Boy, she is fast.
I think that you will find the answers to all of your questions in
Converting to LifePO4 batteries and Sailor Man's LiFePO4 Build. and maybe more you haven't thought about yet.
There are issues on how and where to mount the interior units. One particularly difficult was how to deal with the condensate drain.
Since I been through it all, I am still making final adjustments. The coach's aluminum body was originally separated from the steel chassis with compressive pads. They are there to galvanically isolate the body from the chassis, deal with the different rates of thermal expansion/contraction and their different responses to road shock. Over the decades since manufacture, these compressive pads have been so fatally compress that they are useless. I addressed this issue by replacing them with hockey pucks as per Jm Bound's recommendation.
We did that while installing the new aluminum 75 gallon gasoline tank.
Since we had to jack up the entire coach, we did not anticipate how differently the chassis and body would respond to the jack up process. The flexing stresses actually cracked one of the refrigerant lines and I have been posting recently about replacing the copper refrigerant connections between the body and the compressors with refrigerant rated hoses.
It was particularly difficult to deal with the unit in the salon. Hiding the connections was a real chore and I had make certain that I did not mistakenly cause traps or uphill runs for the refrigerant lines or condensation lines.
I had to purchase an extension package for the salon unit as the lines that came with the mini-split units.
Off course you should get heat pump units not air conditioning units and one that use dc power.
I ungraded my electrical system to provide 51.2vdc to the heat pump units. They are much more efficient.
I also removed the engine driven air conditioning dashboard compressor and replaced it with the much more reliable direct current unit.
The through the bumper tow bar is rated at 15,000lbs but the capacity is reduced by 50% by the Roadmaster spare tire mount. You still have a 7,500lb capacity.
I think that many of your questions will be answered if you read through "Converting" and it will probably generate many more.
I do not engage with Facebook, so I had no idea that some of the photos of my coach had found their way there. Thank you for letting me know.
By the way. I am also considering installing flexible mounts between the exterior units and the supporting custom frame.

Check out my drawings for this mount. You may have to change some of the dimension to match the mounting points on the unit you purchase.

You might also consider the custom mini-split cover I am fabricating from a rotomold water tank. I am just getting started.