Hello Honda-tech family, my name is Gabriel and I have been always a Honda Fan, My first one was a Civic 93, I bought it 0 miles it was a Red, beautiful car, then I had, Pilot, CR-V, and another couples of civics.
Now I have a 2013 civic EX-L I bought it in 2016

which brings me to why I'm writing to you, I'm not a mechanic but the last couple of year I began to learn more and more, and now I think I understand a little more about engines and mechanic, but, and here I go.
The fans on my car are not working when the car is running, if I turn the AC on, they work. I've been checking fuses and relays and searching for schematics to show me how they are suppose to work. and I learn a lot, but now I'm stuck, because the temperature sensor is suppose to trigger the radiator fan relay to close the loop in which both fans would run. if I jump the relay connectors 1 and 2 the fan works and with the ignition on I have power on connector #3 so it means that the #4 leg that goes into A15 pin in the PCM is not grounding. I'm correct to guess that this is because the sensor is bad? and if it is which one is it? #1 or #2? Radiator or the one on top.
I don't know if I was clear enough, but if someone throw me a line I would really appreciate .
by the way the sensor Part number are 37870-RTA-005 Radiator and 37870-RWC-A01 next to the head
The prices on the dealer are $90 and $54. You can find them online way cheaper but either Amazon or Ebay shows that both are the same and interchangeable. weird. Any input on that?
Thanks and happy thanks giving