# Nissan Sentra 2017 radiator fan not working



## mchen33 (6 mo ago)

I added the arctic freezer to the low pressure pipe and the right amount of coolant. Recently, the cooling air is not cold enough. When I switched to the hot mode, the air is hot. So I think the blower motors are good. I found out the radiator fan is not working. The fuse is good after checking using the test light. When I unplugged the harness, the test light did not turn on for all the four pins. Could someone provide some guidance on the causes? The wiring or the coolant temperature sensor or the relay (equipped?)? I do not have the service manual. If someone can send me a copy, that could be great. Thanks.


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## VStar650CL (Nov 12, 2020)

The FSM's after '16 are all HTML and not PDF, so you can only access them by paying Nissan. You can do an IPDM "Auto Active Test" to see if the fan works. To get the IPDM into AAT mode:
Turn the ignition switch OFF.
Turn the ignition switch ON, and within 20 seconds, press the driver door switch 10 times.
Turn the ignition switch OFF.
Turn the ignition switch ON within 10 seconds. After that the horn sounds once and the auto active test starts.

AAT will repeat 3 times with the following items:
Front wiper - LO for 5 seconds → HI for 5 seconds
Parking/Tail Lamps, Front fogs if equipped - 10 seconds
Headlamp - LO for 10 seconds → HI ON ⇔ OFF 5 times
A/C compressor (magnet clutch) - ON ⇔ OFF 5 times
Cooling fan - LO for 5 seconds → MID for 3 seconds → HI for 2 seconds

The medium and high settings get power through a 40A fusible link in Fuse & Relay box next to the IPDM, so if it only runs on low then make sure the link isn't blown. The fan has 3 different relays inside the IPDM to produce the different speeds, so the Blue, Yellow and Lt Green wires should all go hot at some point in the AAT (the Black wire should be ground, if it isn't then that's your problem). If any of the power wires are dead then there's a problem in the IPDM, if they all go hot at some point then there's a problem with the fan. The relays in the IPDM aren't serviceable, so if that's the issue then the IPDM has to be replaced.


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## mchen33 (6 mo ago)

VStar650CL said:


> The FSM's after '16 are all HTML and not PDF, so you can only access them by paying Nissan. You can do an IPDM "Auto Active Test" to see if the fan works. To get the IPDM into AAT mode:
> Turn the ignition switch OFF.
> Turn the ignition switch ON, and within 20 seconds, press the driver door switch 10 times.
> Turn the ignition switch OFF.
> ...



Thank you. Is there any way to connect the +12 V power to the radiator fan directly? There are 4 pins and I do not know how to connect.


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## VStar650CL (Nov 12, 2020)

The pin with the Black wire is ground. Connecting 12V to any of the other 3 pins with ground connected should spin the fan at one speed or another. If any or all of the three don't spin it, the fan is bad.


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## mchen33 (6 mo ago)

VStar650CL said:


> The pin with the Black wire is ground. Connecting 12V to any of the other 3 pins with ground connected should spin the fan at one speed or another. If any or all of the three don't spin it, the fan is bad.


Thanks. The radiator fan costs about hundreds of bucks. First step is to make sure whether it is broken or not. I will check the AAT afterwards. 

Thank you again.


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