Radiator fans stays ON all the time! Why?
 

My radiator fans will not stop running at all. It starts even in the morning when the engine is cold to touch, as soon as I start the car.

Can someone please point me in the right direction and tell me why this is happening and what I should look out for?

Thank you in advance for your feedbacks.

Re: Radiator fans stays ON all the time! Why?
 

Bad relay maybe?

Re: Radiator fans stays ON all the time! Why?
 

If you just bought the car and that was happening from the beginning, I would say the relay or one of the heat sensors failed and it's wired on to cool.

If it just started happening, I would check the relay and the fan switch that grounds the fan to turn them on.

The car will run normally with the fans on, it just might take slightly longer for the car to warm up on a cold morning to get heat to the passengers compartment.

Re: Radiator fans stays ON all the time! Why?
 

I just got a code reader and scan the computer and got the following codes:
P0118, P2183, P0128 !!! Don't know what these means and don't know where to start... please help. Thank you.

Re: Radiator fans stays ON all the time! Why?
 

Hello,
So under the hood, fuse seem to be okay (not blown), and on the bottom of the radiator I find the ECT sensor 2 and I unplug it and the fan stops spinning but I am not sure if the sensor is bad! What to do? Thank you.

Re: Radiator fans stays ON all the time! Why?
 

Okay, so I find this sensor on the bottom of the radiator, I unplug the connector and the fan stops; now my question is: how do i know that this sensor is bad? What else should I look for or troubleshoot? Thank you.

Re: Radiator fans stays ON all the time! Why?
 

I am guessing the grounding is okay since the fan is running, otherwise the fan will not turn on, right? Thanks.

Re: Radiator fans stays ON all the time! Why?
 

your ECT (engine coolant temperature) sensor is bad...have that replaced

Re: Radiator fans stays ON all the time! Why?
 

Hi, thx for the reply...
Is this sensor located on the bottom of the radiator or the one on the engine block? Thank you.

Re: Radiator fans stays ON all the time! Why?
 

i believe its the one on the bottom of your radiator...not 100% sure though

Re: Radiator fans stays ON all the time! Why?
 

I thinks Bee Guz has a point, if you just got this car and from the start it your fan turns on, have it check by an electrician for wire troubleshooting. It is possible your electrical wiring is tap up directly to the battery due to the bad or sensor failure of the ECT.

Re: Radiator fans stays ON all the time! Why?
 

^ this

Re: Radiator fans stays ON all the time! Why?
 

engine block

Re: Radiator fans stays ON all the time! Why?
 

Side note: Stock, what is the default temp set at for when fans are supposed to run?

Re: Radiator fans stays ON all the time! Why?
 

195 per manual, but when you purchase a thermostat from a place other than the dealer they're 180 degrees.

Re: Radiator fans stays ON all the time! Why?
 

Thanks. I need to get a more specific temp gauge, without breaking the bank

Re: Radiator fans stays ON all the time! Why?
 

there are two...the top one is sensor 1 and the bottom one is sensor 2. sensor 2 is the one causing the problem, there is a TSB on this, so id start off replacing the one on the radiator and not the block.

Re: Radiator fans stays ON all the time! Why?
 

Re: Radiator fans stays ON all the time! Why?
 

Hi Guys, Thank you all for your help. I changed both sensors (engine block and the one on the bottom of the radiator) and the problem has been resolved. I can see the difference in car's performance. It's running much smoother and should see mileage improvement also. Again, thank you very much.

Re: Radiator fans stays ON all the time! Why?
 

Thank you.

Re: Radiator fans stays ON all the time! Why?
 

:thumbup:

Re: Radiator fans stays ON all the time! Why?
 

Can someone please help me, is the fan ment to stay on? How much does it cost to replace thermostat as someone said that it might need changing. I also took it to Halfords battery and altonor is fine. Engine working fine but some people have noticed the fan is on. Very wary don't know how dangerous this is and the cost.is the fan not Ment to turn on as the engine goes on regardless of how cold it is?

Re: Radiator fans stays ON all the time! Why?
 

I'm also having the same issue on my newly acquired 07 Civic ES but I'm not seeing any fault codes via OBD - is this normal?
Thanks :thumbup: