Re: Overheat fan in hyper drive
Your jeep has a hydraulic cooling fan setup. This fan idles at about 500 rpm as soon as you start the engine. If it runs at high speed, then it can be that a wrong sensor input is received. The inputs to control the fan solenoid are coming from the engine coolant temp sensor, the transmission temp sensor, the airconditioning pressure sensor and battery temp sensor. When the signal for the engine coolant is not received. The cooling fan will go automatically to high speed mode.