In hot weather only and only when I've been driving errands at city speed, eventually car won't start. It can be jump started & doesn't need a charge, or I can cool radiator and car will start, tho temp never registers over midline on guage. Using accessories, lights & AC esp., aggravates the problem. This only happens when air is over 90 degrees.
This isn't a battery, alternator, generator or starter problem. Last year someone suggested a cheap part, I think "temperature core (coil?) sensor". I can't locate this young man, who is the first person who's ever heard of this problem (his father's GM product, Cadillac I think). I need to know for sure the name of the part before I go back to dealership. (They've been quite honest in "We've never seen anything like this") It's hot, and after 3 years of this, I'd like to use my AC again.