Radiator Fan Motor Runs 20 Min with Cold Engine
06-21-2010, 08:52 AM
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Radiator Fan Motor Runs 20 Min with Cold Engine
I have a 93 Honda Accord SE that has one of the two cooling fans that run for 20 minutes or so everytime the engine is turned on and off (even if the engine is cold and runs for 10 seconds). I believe it is the radiator fan motor that is running excessively as it is on the passenger side of the vehicle.
When I disconnect the Engine Coolant Temperature Switch B (cooling outlet with top radiator hose connection) the fan (only the passenger side fan)stops. Plug the switch back in and the fan starts up again.
I thought it may be the Temperature Switch B but running the one fan for twenty minutes leads me to believe it may be an issue with the Radiator Fan Control Module?
I am sensing the problem may be with the Engine Coolant Temperature Switch B or the Radiator Fan Control Module but am not sure how to root cause the issue further. This is my first posting here, so I really appreciate any help. Thanks a lot.
When I disconnect the Engine Coolant Temperature Switch B (cooling outlet with top radiator hose connection) the fan (only the passenger side fan)stops. Plug the switch back in and the fan starts up again.
I thought it may be the Temperature Switch B but running the one fan for twenty minutes leads me to believe it may be an issue with the Radiator Fan Control Module?
I am sensing the problem may be with the Engine Coolant Temperature Switch B or the Radiator Fan Control Module but am not sure how to root cause the issue further. This is my first posting here, so I really appreciate any help. Thanks a lot.
06-21-2010, 11:16 AM
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Re: Radiator Fan Motor Runs 20 Min with Cold Engine
Problem: The fan runs continuously (longer than 19-minutes) when the key is removed. The symptom is a dead battery. The fan turns off only when the ignition is turn off then on. 99% chance the fan timer is bad. Usually happens to the 90-93 Accords.
Solution: The reasonable solution is to replace the timer control unit. Before replacing the unit it would be prudent to troubleshoot. When the fan does not turn off after 15 minutes swap the cooling fan relays in the engine fuse compartment with another identical relay. If the fan refuses to turn off replace the fan timer unit.
Replacement: Remove the access panel on the driver's kick panel and search for a box way in there the size of two cigarette packs with 8-terminals. The 86-89 Accord fan timer unit is located under the passenger seat. Unbolt the unit and swap it with a new one.
Note: the fan timer location is a bit more to the right compared to this image. It's right next to the main relay like this image (as seen the main relay removal page.)
Solution: The reasonable solution is to replace the timer control unit. Before replacing the unit it would be prudent to troubleshoot. When the fan does not turn off after 15 minutes swap the cooling fan relays in the engine fuse compartment with another identical relay. If the fan refuses to turn off replace the fan timer unit.
Replacement: Remove the access panel on the driver's kick panel and search for a box way in there the size of two cigarette packs with 8-terminals. The 86-89 Accord fan timer unit is located under the passenger seat. Unbolt the unit and swap it with a new one.
Note: the fan timer location is a bit more to the right compared to this image. It's right next to the main relay like this image (as seen the main relay removal page.)
06-21-2010, 01:37 PM
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Re: Radiator Fan Motor Runs 20 Min with Cold Engine
Problem: The fan runs continuously (longer than 19-minutes) when the key is removed. The symptom is a dead battery. The fan turns off only when the ignition is turn off then on. 99% chance the fan timer is bad. Usually happens to the 90-93 Accords.
Solution: The reasonable solution is to replace the timer control unit. Before replacing the unit it would be prudent to troubleshoot. When the fan does not turn off after 15 minutes swap the cooling fan relays in the engine fuse compartment with another identical relay. If the fan refuses to turn off replace the fan timer unit.
Replacement: Remove the access panel on the driver's kick panel and search for a box way in there the size of two cigarette packs with 8-terminals. The 86-89 Accord fan timer unit is located under the passenger seat. Unbolt the unit and swap it with a new one.
First, please accept my appreciation for your timely post.
I seem to be experiencing my problem (rad fan runs twenty minutes and then stops) under all temperature conditions even with a moring start. I think the problem you described is when the fan never stops? My rad fan (not condensor fan - it did not come on) runs even if you start the car for seconds and then turn it off.
Any different thoughts with this information? Thanks.
Note: the fan timer location is a bit more to the right compared to this image. It's right next to the main relay like this image (as seen the main relay removal page.)
Solution: The reasonable solution is to replace the timer control unit. Before replacing the unit it would be prudent to troubleshoot. When the fan does not turn off after 15 minutes swap the cooling fan relays in the engine fuse compartment with another identical relay. If the fan refuses to turn off replace the fan timer unit.
Replacement: Remove the access panel on the driver's kick panel and search for a box way in there the size of two cigarette packs with 8-terminals. The 86-89 Accord fan timer unit is located under the passenger seat. Unbolt the unit and swap it with a new one.
First, please accept my appreciation for your timely post.
I seem to be experiencing my problem (rad fan runs twenty minutes and then stops) under all temperature conditions even with a moring start. I think the problem you described is when the fan never stops? My rad fan (not condensor fan - it did not come on) runs even if you start the car for seconds and then turn it off.
Any different thoughts with this information? Thanks.
Note: the fan timer location is a bit more to the right compared to this image. It's right next to the main relay like this image (as seen the main relay removal page.)
06-21-2010, 05:50 PM
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Re: Radiator Fan Motor Runs 20 Min with Cold Engine
I wanted to add the following:
1.) I disconnected the front engine coolant temperature switch B when the rad fan is running and the fan stops. The fan resumes running when the switch is connected back.
2.) I disconnected the rear engine coolant temperature switch A when the rad fan is running and the fan continues to run. The fan continues to run when the switch is connected back.
Based on this study, I think the engine coolant temperature switch B (coolant outlet) is shorted and needs to be replaced.
Any comments?
1.) I disconnected the front engine coolant temperature switch B when the rad fan is running and the fan stops. The fan resumes running when the switch is connected back.
2.) I disconnected the rear engine coolant temperature switch A when the rad fan is running and the fan continues to run. The fan continues to run when the switch is connected back.
Based on this study, I think the engine coolant temperature switch B (coolant outlet) is shorted and needs to be replaced.
Any comments?
06-27-2010, 10:21 AM
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Re: Radiator Fan Motor Runs 20 Min with Cold Engine
I wanted to let everyone know I replaced Engine Coolant Temp Switch B (closest to the radiator) and the problem has been resolved. Cost $50 at Honda parts. O-ring was included with the part.
Please note: the recommendation to replace the cooling fan timer was NOT the root cause of the issue. Good thing I thought about the problem before spending over a hundred dollars on the wrong part.
Please note: the recommendation to replace the cooling fan timer was NOT the root cause of the issue. Good thing I thought about the problem before spending over a hundred dollars on the wrong part.
06-27-2010, 12:42 PM
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Re: Radiator Fan Motor Runs 20 Min with Cold Engine
Yeah I just copied and pasted from here: http://www.techautorepairs.com/overheating.html, I'll have to email them the link to this thread so they can update their site, thanks!
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