Every vehicle maker, cars, trucks, RVs, doesn't matter, every one of them, in order to save money, installs the same wiring harness in every vehicle of any particular model. All the wires for every possible option and special-order gewgaw is in that wiring harness, and if you don't happen to have that particular option, then you will have dead-end wires that may or may not have a plug of some sort on the end. This policy saves money because instead of 300 different wiring harnesses to stock and possible confusion on the plant floor, they just put the same harness (on which they get the volume price) in everything.
Since nobody can possibly order EVERY option (some of which are mutually exclusive), everybody is going to have those dead end wires somewhere. In the OP's case, maybe they are for solar. Or maybe not. A servicing dealer could tell you. But they are nothing to worry over.