I have an 06 nissan sentra with 170k miles and I've noticed that my dual engine fans only turn on when air conditioner or heater is turned on. Is this a normal operation? I've done some replacements and repairs and I honestly can't remember if they come on upon start up or not. I have not driven it too far as I do not want to be stuck somewhere too far from home. And I don't see the engine temp get too high. I've replaced temp sensor, water pump, thermostat, the bad alternator it had, the battery, and the fan relay switches. Please help. Thank you!
Your '06 Sentra has dual fans.
They always run together. They'll both run on low speed or they'll both run on high speed.
One fan never runs without the other fan running too. (unless one of the fans is broken).
They will not run when you start the car when the engine is at or below operating temperature.
The nice thing about Nissan is that they have an Auto Active Test which you can easily perform to test the functions of the IPDM (which includes the cooling fans).
Here's the drill:
Open the hood. (not part of the test but you want to be able to look at the fans to see that they're both turning).
With the Drivers Door open, turn the key to ON.
Press the Door Ajar Switch 10 times.
Turn the Key OFF and then back to ON again.
The test will begin and you'll hear the horn honk.
The wipers, parking lights, headlights, compressor clutch, and cooling fans (low speed and high speed) will cycle on and off during the test. (some other stuff will cycle on and off too but I don't remember all of them).
You can search "Nissan Auto Active Test" or "Nissan Self IPDM Test" on youtube to see guys doing this.
So if both fans work on Low Speed and High Speed during the test and the computer isn't setting any codes for your ECT sensor circuit and your temp gauge seems to be working then you're good to go
If the engine temp is normal then that's all that matters.
We're getting into Winter so the fans won't be on very much.
I noticed it during the hot summer when it had stalled and went into limp mode due to a bad alternator. Same thing after I replaced it. It ran for 20 minutes on a hot day at idle and still no fan.
well then maybe it should be diagnosed with a professional diagnostic tool.
Thank you for your response.
I mean is it bad to drive with the fans switching on and off for a little while until I get it hooked up to a high dollar scanner? I don't know if one of the fans should be running constantly.
as long as you watch the engine temperature , I think you should be ok for short drives
I don't know if one of the fans should be running constantly.
Not unless your engine was running too hot constantly.
