Does fan motor (cooling system under the hood) is somehow related to A/C fan (inside car's cabin)?
I own a 1999 KIA Sephia LS with aprox 100k miles. As a new issue, the car had overheated 2 times in heavy traffic and I noticed that the A/C fan doesn't work during those eposides. My mechanic believes the problem is caused by the fan motor but it does not make any sense to me due to the coincidence with the A/C fan, which it was working fine till now tat it suddenly stops and, after a few moments, restarts by itself. Does the fan motor (cooling system, under the hood) is somehow related to A/C fan (inside car cabin)?
second post, scary. yes this is a bad thermostat. check your coolant level.
the electric fan, inside the cabin, only can throw heat when there is heat to throw that gets there thru engine heat....when the engine reaches 170 degrees is supposed to open and let the coolant loop realize the heater core (or heat exchanger)...now the engine fan blasts across the engine radiator keeping the engine from overheating....some cars use an electric fan, and some use one fitted onto the front of the engine. if either of these would stop doin' their job, you'd overheat combined with low-coolant or jammed thermostat could produce what you are experiencing...I know it seems like a stretch, but these combinations of dysfunction can explain logically what you are experiencing.
Yes, the electric cooling fan(s) are supposed to come on when your coolant temperature rises to a certain point. Usually around 220°F. Or when you switch on the air conditioning. Some systems are set up so the radiator cooling fans run constantly when air conditioning is selected. Others switch on & off with the air conditioning compressor. I believe your mechanic is correct in that your car is overheating because the radiator cooling fans aren't coming on. HTH. -Jim