92 Cav. overheated replaced thermostat now dies for no reason

[gargamel34]

Last week my 17 yr. old daughter calls says her 92 Cav. got hot, like way over to the red. I came checked it, coolant was ok, car gets hot when sitting still, cools when you take off. So I figured well its an old car, let's change the thermostat. Replaced it, I test drove the car, it was fine. She leaves for school, car dies on the highway, she says it wasnt gettting hot by the temp gauge. I check the coolant, a little low, nothing major considering I had flushed the system and changed the thermostat.
I get the car home, noticed the electric cooling fan wasnt coming on at all, so wired it to come on with the ignition switch. She drives it not even 2 miles the car dies for no reason and will not restart itself until you let it sit.

I checked the codes through the plug by the fuse box, got no codes.

It was suggested to me that the coil packs might be bad, getting hot and shutting down when the engine gets warm.

This car has 221, 000 miles on it, my daughter works at Kentucky Fried Chicken for minimum wage so she doesnt have a lot of money to waste on coil packs if thats not the problem.

Anyway, what are the chances that it is the coil pack and is there anyway to check them without removing them?? they are in a really screwed up place .. And would the coil packs being bad kick back a code or not?? the only code I got out of the thing was 12 which tells you the module is working.