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Radiator fan wont shut off... help!

  #1  
Old 01-08-2009, 12:15 AM
thedaveman89's Avatar
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Default Radiator fan wont shut off... help!

As of today my radiator fan continues to run with the key out of the ignition...

its a:
96' Accord LX
112k on the engine... 150k on the rest...

when i pull the fuse that controls the fan it shuts off the fan.. but if i connect the fuse again (with the car still turned off) the fan starts up again....

any ideas? ... hope this is a simple fix...
 
  #2  
Old 01-08-2009, 05:53 AM
Join Date: Oct 2008
Posts: 46
Default RE: Radiator fan wont shut off... help!

It's supposed to do that if the coolant is still too hot.
The fan might stay on for up to 10 min after you remove the key.
If longer than that, it might be a faulty fan timer unit (it's a small black plastic box immediately behind the glove box, it's the size of a pack of cigarettes)...
Hope this helps
 
  #3  
Old 01-08-2009, 07:29 AM
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Default RE: Radiator fan wont shut off... help!

Try this test...

Find the fan switch (sensor) on the UPPER radiator hose nozzle, where the upper hose connects to the head.
Run the car, but NOT long enough to really warm up.
Turn off the engine - presumably the fan will run.
Unplug that sensor.
Tell us whether that madethe fan turn off.
 
  #4  
Old 01-08-2009, 11:13 AM
thedaveman89's Avatar
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Default RE: Radiator fan wont shut off... help!

i haven't had time yet to do the other tests you mentioned...

don't know if this helps anymore... but today i went out to my car cold and put the fuse in that i took out to stop the fan... with my car completely cold the fan starts up again as soon as i attach the fuse
i also unplugged the only wire i could see going from the fan and that also shuts it off..


any help there?
 
  #5  
Old 01-08-2009, 11:28 AM
Join Date: Oct 2008
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Default RE: Radiator fan wont shut off... help!

it's either a faulty thermo-switch as Jimblake mentioned or a bad fan timer unit.

To check the thermo switch, put again that fuse back and check if unplugging the switch makes the fan stop, the switch in on the upper rad hose, behind the radiator (red circle on attached pic).
There is another switch on the thermostat housing(blue circle), but that one works only with ignition on.

The 2 switches have different temp values (106 vs 92 i think) and thus are not "switchable", but in your case, just to make sure, you could swap these 2 switches for 5 minutes and see if it does any good... Do not drive with this setup, put everything back before you use the car !

If this doesnt help, then check your fan timer unit.

[IMG]local://upfiles/18533/F0BCEDAA2AB041C4A2D5E685821D4FEF.jpg[/IMG]
 
  #6  
Old 01-08-2009, 12:15 PM
JimBlake's Avatar
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Default RE: Radiator fan wont shut off... help!

You put the fuse in & the fan started up... Had you turned on the ignition switch AT ALL?

If not, it seems the fan timer (at least)is bad. Its job is to turn OFF the fan after 10 minutes or so, in the event that switch is stuck ON. That 10 minutes starts counting when you switch OFF the key.

Do you have a multi-meter? You could also use the CONTINUITY function to check those switches (both of them). They should be OPEN-CIRCUIT when the engine is cold.
 
  #7  
Old 01-08-2009, 04:45 PM
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Default RE: Radiator fan wont shut off... help!

i had not touched the ignition switch at all.. in fact i hadn't even opened my doors yet when i plugged the fuse in to test that this morning..

I also tested and unplugged both of the Thermo switches pictured in the photo.. both tested out fine and the fan continued to run with them both, and individually unplugged...

sorry i'm such a newb, but could someone show me a picture of where the fan timer unit is located?

 
  #8  
Old 01-08-2009, 05:06 PM
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Default RE: Radiator fan wont shut off... help!

.
 
  #9  
Old 01-08-2009, 05:06 PM
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Default RE: Radiator fan wont shut off... help!

I have no pic for the fan timer unit location. but it's easy to find.
First, remove the glove box, to do that, you will need to open the clips on both sides, + a small screw on the right outer side of the glove box, it's that simple.

there is a lot of stuff back there behind the glove box, what you are looking for is some kind of aluminium/stainless steel rail that runs horizontally behind the glove box, this rail is about 1 inch wide.
The fan timer unit is attached to that rail, behind it. it's a small black box with 1 connector on the right side.
Take a small screw driver and press the round button in the middle of the fan timer then slide it upward.
you can then take it out, unplug it and see if the fans still run. (u can actually try to unplug the fan timer without even sliding it out, but i always find it easier to get it out and make a little further inspection...)
You can get a fan timer on ebay for less than 20 usd
good luck, keep us updated

[IMG]local://upfiles/18533/AC202042B1624A3993F74D92CFC0FE98.jpg[/IMG]
 
  #10  
Old 01-08-2009, 05:30 PM
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Default RE: Radiator fan wont shut off... help!

I hope this info helps you;



[IMG]local://upfiles/5417/DB1FDE5D23E24D84A36F2E649E31863A.gif[/IMG]
 

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