If the cooling fan is turning slow on a vehicle then the motor is dying. The fans should be replaced in order to avoid an overheating issues that can arise in the engine.
if cooling fan is not turning on you need to check fuse. then check fan thermostat . and switch, can also be bad motors check them.
probably the fan relay
No power to fan, fan motor is burned out, fan motor has seized up, control circuit for fan not working.
You may have a bad or weak cooling fan sensor.
There is no cooling fan sensor, ECM is turning the fan on and off. Between the ECM and fan there is a relay, located in front of the car on the left side behind the left headlight,it's the fourth relay from the inside out.
The cooling fan may be inoperable, either the fan clutch is bad or the electric cooling fan isn't working. Need to know what year, make and model vehicle you have to help you more.
This sounds more like a bad cooling fan than a vacuum problem. Insure your fans are turning and are not slipping.
cooling fan
Your cooling fans are not coming on, or the clutch fan is bad.
the engine temperature has to get to 225 degrees Fahrenheit to turn on. If the engine is reaching 230 degrees and it is not turning on the sensor for the engine cooling fan is most likely the culprit. As for the fan operation of the fan with the a/c that is normal
Make sure it is not the temperature sensor, somtimes when they fail it wil never turn on the fan. If you can test the fan to make sure it actually works. You can usally test the fan motor to see if it work by turning the ac on, which wil automatically turn the fans on by default.
The 2004 Dodge Intrepid cooling fan relay switch can be found on the back of the cooling fan motor. The cooling fan relay switch is attached to the fan motor with two retaining screws.