Haven't you heard of Kentucy Yankies? The Florida Keys are the ONLY southern "states" that I know of! True it does not get as cold as New Jersey, and north of there, but it is COLD even in N. FLA. Anyway... There are a few things that may be causing your problem. First I would suspect the on board computer itself. If you run voltage down below acceptable limits to the computer there is a law of electronics that replaces the lack of voltage with increased amperage; meaning the computer may have toasted a process needed to function. There are also a dozen or more reasons for the trouble you are having, and I feel the DEALER should spend more time looking for the problem instead of starting it in the morning, letting it idle until lunch, and calling you to say it is fine! I mean NO offense to anyone involved. Intermittent problems can ONLY be found with time or changing EVERY part involved. In either case the "dealer" doesn't make out! Keep your patience, and it will work out. Safe trip to the south, and if you decide you need a puppy to bring home w/ you, I have the prettiest pups ever. Ready to go...