You have an option on your engine of an electric fan or a viscous coupled fan. Based on what you are describing I suspect you have the viscous option which means the fan is connected to the engine through a metal coil spring and as the coil is heated, it increases the speed of the fan.
More than likely something inside the clutch has failed which is why you are able to stop it. Either way, you will need to replace the fan clutch.
I included the procedure on how to replace the clutch. Please let me know if you have other questions on this issue. Thanks
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Friday, June 21st, 2019 AT 5:20 PM