At the moment it is heated active by means of the temperature sensor that sends an electrical pulse to the engine control module that is located in the center of the console (board) I create the lower part, now as it had commented you handle 2 velusities the engine may be burned the first of the fans or in its burned or burst the fuse that feeds the relay of the first one is a fusable Conventional that coneses, the Link fuses go on the cable on one side has the current of the other not if it were the case the cable is troy and put a normal fuse of 30 amps that is indicated.
Although it could be the case that everything is good and what happens the temperature meter throws an incorrect reading or how you say it marks three quarters but it could be that it is in half and you break your head looking for a problem that is not saved the temperature reading.
If you know of electricity I could provide you with the temperature cross diagram of the Altima I have the GLE, GXE, SE, I don't know what yours is yours.