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Fan Comes On After Vehicle Shut Down
Thread Starter
Honda-Tech Member
Joined: Nov 2005
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From: Northwest ID, ID, USA
Fan Comes On After Vehicle Shut Down
1995 Accord LX
I noticed today that after I turned the car off the fan ran for about 10 mins and then shut down and has been doing the same thing each time I drive since. The temp gauge is about 3/7th, basically alittle less than half way up, and stay steady. Why is the fan running after I shut down, it rarely ever did this before ? It also seems to not want to come on at idle but immediately after I turn the car off after idling for awhile the fan will come on and run for 10 mins or so.
I noticed today that after I turned the car off the fan ran for about 10 mins and then shut down and has been doing the same thing each time I drive since. The temp gauge is about 3/7th, basically alittle less than half way up, and stay steady. Why is the fan running after I shut down, it rarely ever did this before ? It also seems to not want to come on at idle but immediately after I turn the car off after idling for awhile the fan will come on and run for 10 mins or so.
Last edited by kornerk12; Mar 28, 2010 at 07:06 AM.
Thread Starter
Honda-Tech Member
Joined: Nov 2005
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From: Northwest ID, ID, USA
Re: Fan Comes On After Vehicle Shut Down
yes but this seems odd just because it never happened before and why does the fan turn on after the car is off but was not on while the car was running ?
Honda-Tech Member
Joined: Aug 2006
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From: Orange County, CA
Re: Fan Comes On After Vehicle Shut Down
Are you missing coolant? Supposedly, if you're driving on flat roads or any condition. The needle should be around 2/5, with A/C on or not.
Might want to check your cooling system.
Might want to check your cooling system.
Honda-Tech Member
Joined: Mar 2010
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Re: Fan Comes On After Vehicle Shut Down
I don'tthink this is normal. I recently bought another accord and the fan would turn on once i turned the car off. About a week or two later i replaced the thermostat and now the fan doesn't turn on when the car is off.
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Joined: Jan 2007
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From: West Chester, Ohio, USA
Re: Fan Comes On After Vehicle Shut Down
It is normal. When you shut the engine off, it stops circulating coolant. The heat in the block will continue to heat the coolant in the engine. If the temperateure gets high enough, the fan will come on until the coolant temperature drops.
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Re: Fan Comes On After Vehicle Shut Down
flush your coolant out with new stuff if its been over 30k miles since the last time. make sure to bleed ALL air from the system by loosening the bleeder screw and letting coolant come out until its a stead flow. tighten the bleeder screw. take off the cap of the radiator. turn your car on and turn the heater on full blast. let it run until the fan comes on twice. while you are waiting, squeeze all the larger coolant hoses. you will probably see some additional air bubbles come out. if that doesnt fix your problem, try replacing the thermostat, could be getting gummed up and not opening the valve properly. its a cheap and VERY worth it fix. cars get detroyed from overheating FAST, so dont mess around. 
Thread Starter
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From: Northwest ID, ID, USA
Re: Fan Comes On After Vehicle Shut Down
I actually just replaced my thermostat and all the coolant in the radiator. Its a Stant thermostat 180 degree. The same exact one that was in there previously. I loosened the bleeder screw and there was a steady flow. The only problem was I could not get the fan to cycle. I let the car run for about 0.5 hour at idle with the cap off burping the system, and squeezing the upper hose many times. I have driven the car about 20 miles so far, and check the level, its good and overflow is good also.
As far as something relating to the battery causing this, how could this be ?
As far as something relating to the battery causing this, how could this be ?
Honda-Tech Member
Joined: Jul 2007
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From: somewhere in, NJ, USA
Re: Fan Comes On After Vehicle Shut Down
the are 2 fan switched one controls the fans when car running the other when car off...they are located on the engine side of the upper and lower rad hoses....for the life of me i cant remember which ones on n which ones off but im sure someone will chime in with it
Thread Starter
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From: Northwest ID, ID, USA
Re: Fan Comes On After Vehicle Shut Down
the are 2 fan switched one controls the fans when car running the other when car off...they are located on the engine side of the upper and lower rad hoses....for the life of me i cant remember which ones on n which ones off but im sure someone will chime in with it
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Joined: Feb 2010
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From: St Louis, MO
Re: Fan Comes On After Vehicle Shut Down
u actually have a switch for ur gauge and another to turn the fans on and off. buutt u also have an oil temp sensor which will turn the fan on. either way the computer will turn the fan on if temps reach 225(its around there) on either sensor. even with the car off. as for it being okay, its not. u should check ur sensor resistance or cooling system performance. and my cd5 only gets to half way on the gauge. 3/4 is high
Thread Starter
Honda-Tech Member
Joined: Nov 2005
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From: Northwest ID, ID, USA
Re: Fan Comes On After Vehicle Shut Down
u actually have a switch for ur gauge and another to turn the fans on and off. buutt u also have an oil temp sensor which will turn the fan on. either way the computer will turn the fan on if temps reach 225(its around there) on either sensor. even with the car off. as for it being okay, its not. u should check ur sensor resistance or cooling system performance. and my cd5 only gets to half way on the gauge. 3/4 is high
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Re: Fan Comes On After Vehicle Shut Down
It's normal. You can read about it here: http://techauto.awardspace.com/overheating.html
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Re: Fan Comes On After Vehicle Shut Down
When you bleed your coolent system for air, you do the bleeder screw which i see you already did, but you also need to take your radiator cap off and runs the car with the heater on full blast usually to get your fan to turn on, after it turns on twice pop the cap back on and try to see if that fixes the problem, the coolant system is really picky. I usually just pop a small sized hole in my thermostat to get the air out.
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From: Australia
Re: Fan Comes On After Vehicle Shut Down
The fans coming on is normal, but the reason it's doing it more noticeably is because you are running hotter. That's almost certainly because you haven't bled your cooling system for air properly. It's a very common reason for engines to run hotter than they should.
Bleed the coolant of air properly and your fan activity will go back to how they were previously.
Bleed the coolant of air properly and your fan activity will go back to how they were previously.
Honda-Tech Member
Joined: Feb 2010
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From: St Louis, MO
Re: Fan Comes On After Vehicle Shut Down
It's normal. You can read about it here: http://techauto.awardspace.com/overheating.html
Proper operation: A number of Honda/Acura with an advance cooling system employ a fan timer system to offset the fragile aluminum head. The timer allows the condenser fan to know when and how long the fan should operate. By switching the ignition off and the coolant temperature exceeds the boiling point the radiator fan will kick in. (However, both the condenser fan and the cooling fan will run when the A/C is on at any temperature.) The fan timer should run for almost exactly 15 minutes and 18 seconds if the engine temp is over 223F. If it is running less than or greater than 15 minutes, or the fan going on/off randomly while the ignition is on or off then either the fan timer is bad, the fan relay, or perhaps there's a bad connection somewhere. If the fan timer system fail to turn on the fan, serious damage to the head and head gasket could occur some time in the future.
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.
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.
Thread Starter
Honda-Tech Member
Joined: Nov 2005
Posts: 1,177
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From: Northwest ID, ID, USA
Re: Fan Comes On After Vehicle Shut Down
The fans coming on is normal, but the reason it's doing it more noticeably is because you are running hotter. That's almost certainly because you haven't bled your cooling system for air properly. It's a very common reason for engines to run hotter than they should.
Bleed the coolant of air properly and your fan activity will go back to how they were previously.
Bleed the coolant of air properly and your fan activity will go back to how they were previously.
Honda-Tech Member
Joined: Oct 2009
Posts: 223
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Honda-Tech Member
Joined: Jul 2007
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From: somewhere in, NJ, USA
Re: Fan Comes On After Vehicle Shut Down
as i said dude the fans are controlled by switches.....and it IS normal for them to run after the car is off i have a 90 and a 96.....but if ur fan switch is bad for the car running the car may be running slightly hot but not hot enough to notice and requires extra cool down...replace the fan switch(s) and you should be fine...i say both because yes the one isnt turning the fans on when the car is on but the other may be keeping them on to long when the cars off
be professional
Joined: Oct 2002
Posts: 14,842
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From: Pittsburgh, PA
Re: Fan Comes On After Vehicle Shut Down
The Stant single-stage thermostats you can buy in most chain parts stores do not work properly in Honda cars. Period. If I had a dollar for every cooling system problem I've seen caused by one of those, I wouldn't have to work.
Go to a Honda dealership and buy an OEM two-stage thermostat. Honda OE thermostat suppliers are Nippon Thermostat and Fuji Thompson. They work properly.