Cadillac Repair: car kills, electric cooling fans, cadillac eldorado

Question
I am really dumb when it comes to car's, I am 65 and I know, when a car shop See's someone my age they know they can tell me anything and rip we off pretty easily.So I am hopping I can get some ideas on what to look for from you.

We have a Cadillac Eldorado , it is a 1994 with V-8  and is a 4.6
Do I make any since, because I am just repeating what I was told.

I notice that my temperature was staying up around 200 for a long time now, and yesterday my car killed while at a street light. the temperature had gone up to 230.I got it started and got it back home but when I shut the key off it dieseled./keep running for a short time. I went to auto zone and they said they could find nothing wrong with it, I don't know what to look for now. have you any suggestions?  any help is so, very much ,appreciated .    Thank you, Marie  

Answer
The vehicle is designed to run at temperatures around 220 degrees. The new electronic cars are not like the older cars where they used to run at a temperature of 160 to 180 degrees.

I see nothing wrong with your car either.

Question: are the electric cooling fans running at the radiator when it gets that hot ?.

If they are, I do not see a problem.