We are on a trip 4 hours from home, but I noticed a couple if weeks ago the heater intermittent blowing cold air when it was on even on Max heat. Now I noticed tonight the car maxed out temp on the gauge when idle (no warning lights or chimes went off at all). We had just driven 4 hours on mostly interstate and no issues. It only overheated when we were sitting at a red light off the interstate.

I also notice that the fan runs after the car is off sometimes. I assume that is the cooling fan. I also think I smell a electrical burn smell when the vent is set to outside air.

I haven't looked at radiator yet but I have never seen anything leaking so I don't think it is a leak. Any thoughts? About to have to bring it to an out of town dealership to fix.

With the electrical burn I feel like there is maybe some wiring grounding out or something and that is why the heater sometimes works and sometimes doesn't

 

There is a good possibility there is more than one problem.
This is strictly speculation,
Could be coolant level, water pump, something in the heater control system.
If the engine has been allowed to overheat, that opens the door for a multitude of engine problems which you really don't need or want.

 

I don't think the engine actually overheated. The temp gauge just went all the way up. I immediately killed the engine And waited for the light to turn green and when I cranked it back up it was back down to normal temp.

I'm a little dissapointed in the lack of chimes or yellow or red lights that didn't happen with the temp gauge being that hot. Saw no wanting dash lights at all.

 

An running engine just turned off will have its temperature to continue to rise
As the cylinders are still hotter than the coolant going around the cylinder
So, it depends on how hot it was running and what the ambient temperature it was.

But, would definitely look into the coolant temp level and water pump and thermostat
Good luck.