i got an 87 iroc with a 5.7l and the main fan does not shut off it constantly runs when the car is running. if i turn the key to the on position with it warmed up it doesnt run, but when the engine runs it runs. already replaced all 3 relays and coolant temp sensor and coolant temp switch......any ideas? btw temp is staying low but it seems like the car isnt running right unless i cut power to fan and it warms up like normal relying on thermostat