Hi everyone, I am new to this forum. I have a 92 Accord EX 4-dr 5-speed with 238,xxx miles on it. Immaculate shape since I bought it from an older couple whom were the origional owners.

Anyhow, roughly a week ago I noticed my coolant fan runs for anywhere from 3-5 minutes as soon as I turn my key off to my car...the A/C works and when the A/C is on both fans will run. What is very interesting about all of this is that as soon as I turn my key to the on position when all the idiot lights come on, the fan stops. I turn the key off and the fan starts running again. The car will not do this when cold - only after I drive it.

I tried changing the coolant fan relay but the same thing happens, so for curiosity, I unplugged the plug from this switch that is screwed into the adaptor thing where the upper rad hose meets the engine block, and the fan turned off. I am assuming that this is the "fan switch" ?? Should I just go ahead and try a new switch or is this something normal???

 

The fan is being operated on water temp. That thingy is a temp switch, so it continues to run until the coolant reaches a set point temperature. I have not noticed this on my 2000 with a manual trnsmission, but this is not an unusual setup for cars in general.

 

1992 & 2000 have different fan-control setups.

For 92...
It's not unusual for the fan to run a few minutes after you turn off the engine. Especially hot summer. That fan switch you unplugged is responsible for switching the fan after the engine is turned off.

Follow the LOWER radiator hose back towards the back of the engine. There's another similar switch back there (down low & hidden below the throttle-body). That switch is responsible for switching the fan while the engine is running.

Those 2 switches have different setpoints as well as different locations. That's why the fan turns off when you turn the key ON.

Now for the 2000 Accord...
Beginning in 1998 Honda quit using the 2nd fan switch on the upper radiator hose. The fan control system in 1998-2002 Accord has no provision for running the fan when the engine is turned off.

 

UPDATE - just for kicks I tried starting the car up from it sitting overnight and it only ran for 30 seconds if that, when I turned the car off the fan kicked on! The temp gauge and engine were stone cold! I do not understand this at all...all summer this car did not kick the fan on when the ignition was shut off and now it does it seemingly anytime i turn the car off from the engine running. Any Ideas??

As for the previous insight I truly appreciate the advice!! It does make sense when explained to me...I am just wondering why this happens now when it didnt happen before and also on a cold engine.

 

Coolant temperature sensor B is likely shorting out and needs replaced. If you look in the common DIY thread on top of the gen tech help forum, there is a link to a good write-up by jimblake.

 

Thanks so much for the valuable advice! I went ahead and ordered a new fan switch (the one by the upper rad hose)...hopefully this will stop once the sensor is replaced.

 

Good luck, hope that cures it.