I have a 1994 Honda Accord LX and my radiator fan contiues to run even when the motor is ice cold. All I have to do is start the motor and turn it off, and the radiator fan runs for 20 minutes or more--even ice cold. I checked the relays and fuses. The fans work as they come on and off as they should when the motor is warm. I know there are two radiator fan switches--the radiator fan switch located by the thermostat (A), and the condensor fan swith located by the top radiator hose (B). When the radiator fan runs on and I disconnect the condensor fan switch, the fan stops. I think it must be this switch that needs replacing. I can't get my hand into the motor enough to test the collant temperature sensor for the ECM, but I don't know if I have need to. Why do they call switch (B) the condensor fan switch when it runs the radiator fan? Do you think I am on the right track in replacing this switch (it's not cheap). Any other thoughts. Thanks, Nick.

 

The coolant temperature sensor for the ECU has nothing to do with switching the fans, so don't bother.

You're right,the fan switch at the upper radiator hose is stuck closed. Get a new one. If you're quick, you can swap it in & only spill a few ounces of coolant.

The fan switch at the thermostat (in back) is responsible for switching the fans while the engine is running. The one in front is responsible for switching after the engine is turned off (it has a different setpoint). There's a fan timer module that's responsible for switching between those & also responsible for turning OFF the fan after 20 minutes even if the one switch is stuck (this seems to be OK).

ps. Even the fans names ('radiator' & 'condensor') are misnomers. The radiator & condensor are both full-width, so each fan pulls air thru the radiator & condensor both. The names must be throwbacks to earlier Hondas.

 

Jim,
I want to thank you for your quick reply to my son, who posted last night under the name nitrousnick concerning the cooling fan issue. We have worked on this car all weekend. One mechanic said it could be the fan timer switch (where is that located?), but I agree with you about it being the condensor fan sensor. I am going to order one today and I'll let you know how it turns out. If it is stuck (or faulty), is the reason that the fans do not run continually is that it only becomes operational when the engine is off? Den

 

I haven't owned a '94, this is based on circuit drawings I've seen. I'm not sure exactly, but I think the fan timer module is physically buried in the dashboard somewhere.

It seems clear that the fan switch at the upper radiator hose is bad (stuck "ON") because the fan comes on after shutoff,even when the car isn't anywhere close to warmed up.

It also seems that the fan timer module is OK, based on you saying that the fan runs only about 20 minutes. If itruns forever, draining the battery, then I'd go after the timer module.

Actually, maybe someone around here knows if 20 minutes is the correct time for that timer module to intervene?? There's a couple guys around herewith access to those kind of specs for all different years of Accord.

 

Well, I can share my experience. Mine was the opposite: Fans continue not to run. My problem was a faulty Temp Sensor switch at the end of the lower radiator hose. It was $50 at the dealer.
What I did during the time between the problem occured and when I finally got around replacing it was jumping the terminals on that sensor. This kept the fan running continously until the key is in OFF.

I hope this would help.

 

Geez...I didn't know there was another sensor there (perhaps a relay switch). Well I'll let you know how it turns out. Thanks for your post. Den

 

Patpatpat is referring to the fan switch on the thermostat housing. That's (A) in your son's post above. That one's responsible for switching the fan on & off while the engine is running.

 

Thanks Jim, the condensor fan thermal switch fixed the problem. I'll keep checking the forum to see if I can help others (owned Hondas since 1994) or with new problems. Den

 

This is an old thread but I just came accross it while searching about how the Accord has a (FAN switch A) and a (FAN switch B).

There is some misleading information in this thread that I would like to clear up.

FAN thermoswitch B is not the "condenser fan switch"

My understanding of how the cooling fans are controlled in the Accord, atleast in my 1994-1997 Accord is this:

There is a fan controller/timer that is located behind the glove box in the accord. (You can pull it down without removing the glove box if you needed to replace it.)

The fan controller gets power from the igntion switch on both I and II settings.

The Radiator fan (the bigger one on the passenger side or RH side of the car) is wired to FAN switch A so when the coolant reaches a certain temperature, the switch grounds out and triggers the fan relay to close and allow power to flow through the Radiator fan. Once the coolant is cooled down the switch opens, the relay opens, and the fan shuts off.

FAN switch B is set to ground out at a higher temperature than FAN switch A. It does not trigger the fan relay directly like FAN switch A does. It goes into the fan controller/timer box. Its there so if your engine is running too hot, and you shut your car off, the timer engages and runs your cooling fan for approximately 15 minutes. This is because your under hood temperature is too high.

I live in very hot central Florida and I am on my 4th 1994-1997 Accord (I love these cars) My fans don't come on when the car is off, even on the hottest days. If your system (the fan timer, the switches, the relays) is working correctly and your fan is coming on when you shut the car off, I would try and find out why the engine is not being cooled propertly (clogged radiator fins, partiall stuck thermostat, weak water pump, low coolant, air in the system. etc)

 

good info