# cooling fans will not shut off



## seufeph1 (Nov 20, 2015)

I started off by changing the thermostat and new hoses, after that is when i noticed that the cooling fans were running on high after the car warmed up. My mechanic looked at it tried a new temperature sensor, did not work, tried cleaning radiator and condensor, did not work. I tried another thermostat that was 180 degree and that did not work. So I took it to nissan and they told me that the radiator needed replaced and that all the relays were working like they are suppose to. So I went and got a radiator and installed it and the fans are still running on high. does anyone have an idea what it could be. I am talking to the nissan dealer again and will probably take it in again.


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## derekbrian (Oct 2, 2015)

There is a thermo switch on the radiator, and over time it goes bad. It is found on the drivers side top of the radiator and it screws into the radiator and connected electrically through a plug. You detach the plug, and unscrew the switch bolt when replacing. While doing so disconnect the battery so that your hands will be safe from being caught in fan.It is hard to reach so you need a socket extension to get to it. This solved my problem. You can also take second opinion from top rated Nissan mechanics.


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## smj999smj (Jan 1, 2006)

On some years they did use a switch in the radiator...in later years, it is controlled by the ECM and the fans are sometimes are turned "ON" at all times as part of a fail safe mode. Assuming you plugged everything back in, a dealer would be the best bet to get it diagnosed. I had the same thing happen on an Altima and it turned out to be a faulty ECM; the scan tool wouldn't even communicate with it. Posting a year of your Maxima is helpful when asking a question.


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