I've heard it said many times that electrical problems can be the hardest thing to track down in the vehicle, and that an expensive, complete rewire is often the only way to fix it. This one sounds like it will need the expensive rewire.
So you should ask yourself,
why didn't this dealership do the rewiring before they listed it for sale?? This to me is a red flag. A reputable dealer IMO should not say, if you agree to buy it we'll fix it and stand behind it. Instead I would look for a place that
already took care of known issues and got the unit in tip-top running condition before putting it up for sale.
I bought a used 2008 Lexus with about 85K miles. This model usually needs a new timing belt at 90K, and many mechanics will recommend replacing the water pump at the same time just because it's right there, exposed, when doing the belt. Well, Lexus of Tulsa had already replaced the timing belt and water pump prior to advertising it for sale, even though technically it wasn't even due yet. That is first class IMO, and it let me know they weren't trying to 'cheap out' or foist some hidden problem over on me. (Carfax showed regular scheduled maintenance, too... peace of mind.)
So what I'm saying is, I'd be leery of a place that offers a Class A for sale when they know it needs wiring re-done and they haven't bothered to do it. Look, if they get you on the hook and then do a half-baked repair job on it (which I'd suspect will happen), you could have a lot of misery with it and camping days lost as techs try in vain for hours to track down where the short is located. One bit of exposed wire touching some other metal can cause constant battery drain, for example.
Mike G.
Liberty is meaningless where the right to utter one's thoughts and opinions has ceased to exist. That, of all rights, is the dread of tyrants. --Frederick Douglass
photo: Yosemite Valley view from Taft Point