Hello All,

I purchased a 2003 350z and am having issues with the cooling fans.
I put new aftermarket fans on it and they turn on high & low only during the forced diagnostic test (key cycle & 10x door switch method)
The dash temp gauge appears to work correctly and even turning the AC on does not activate the fans.
Please let me know if you have any ideas or tips on what to check or how to fix.

Thank You!

 

I'd swap in stock fans, and see if that fixes it. Failing that, I'd inspect the relays, and check the voltage. What aftermarket fans did you buy?

 

Thank you for the reply
They are Chinese oem replacement fans. They work when in test mode. High and low tests

When i check voltage on the fan plugs there is nothing unless i put it into test mode.

If the coolant sensor was faulty... would the dash gauge read correctly?

Edit*
Also i replaced all 3 relays and checked fuses

 

I remember reading somewhere that the Z fans always kick on when you turn on the ac. Not sure if that is correct but I can tell you that if you are trying to get the radiator bled it takes forever to get the things to cycle.