Could be a bad temperature sensor
Usually located at the rear of the radiator about 1/3 down from the top
That one should run anytime the a/c is turned on.
Not necessarily. It's more likely a problem with the engine's cooling system: * improperly maintained coolant levels or quality * corroded and clogged radiator * faulty radiator cap * faulty water pump And if it's a newer vehicle with electric cooling fans, you should check to see that the secondary fan starts when the AC is turned on.
The radiator cooling fans are turned on when the heater control is set to defrost.This makes for better and more effective defrosting of the windshield
check your relay for the cooling fan and fuelpump
It can be many things. First make sure the cooling fan is running anytime the A/C is on. the cooling fan should run continuously with the A/C turned on. If not, either the fan motor or relay is bad. If that is not the problem, you need to service the cooling system, and see if the problem disappears. Start by cleaning the front of the radiator of all debris. Now drain the cooling system, flush the system with heater set to hot, and replace the thermostat with an exact match. Pour in a 50/50 mix of the correct Anti-Freeze and bleed all air from the system.
coolant temp switch or fan relay are bad.
When air conditioning or front defroster are turned on it will turn on A/C compressor which requires the A/C condensor to be cooled (via radiator fan).
Perhaps your radiator fan is staying on after the car is turned off. I have recently had this problem, and googled it. And someone else had the same problem.
The 1999 Saturn S-Series engine heats up the coolant, the thermostat valve opens and the coolant circulates between the radiator and the engine. Then the radiator fans turn on to cool it back down. The fans are also turned on when the air conditioner is turned on to aid in cooling the radiator and the air conditioner condensor.
My 1990 Honda Civic Hatchback had a similar problem where it overheated on a seemingly random basis. I first replaced the thermostat, but that did not fix the problem. Then I replaced the water pump, again with no positive result. Finally, I replaced the radiator, which fixed the problem. As it turned out, the radiator had pinhole leaks that caused the problem. Also, when it comes to a leaking radiator, I do not suggest the 'quick fix' of additives to the radiator water that plug holes and stop leaks. These additives can cause more problems than they resolve. The best solution is to replace the radiator.
You need to check the cooling fan relay and the cooling fan switch.it only turns on when needed.other then when you turn the ac on then its always on.The reason the fan runs with the air conditioning is "on" is to keep the high side pressure down. Otherwise it would increase to the point of something blowing out such as a hose or the pop off valve in the compressor. If the check engine light is "on" the it will have a code referring to the problem
Most cooling fans will stay on for a minute or so after turning off the car in warm weather. If they stay on past a minute or so, then there is a problem.