Cooling fan runs all the time... noisy and annoying.

*edit* It was the 'Radiator Fan (Temperature) Switch'... in the engine block.

It is most likely one of the following (part names from Autozone).

Thermostat - $11.99
* Doubt it. All that does is allow the flow of fluid or not. Does it control if the fan runs? I don't think so...it's just a spring and some caps I think.

Electric Fan Thermostat - $24.99
* Sounds better. Looking for something that would tell the fan to run.

Cooling Fan Switch - $15.99
* Could be stuck open/on. Takes the top spot/close contender with Electric Fan Thermostat depending on, historically, which one normally wears out.

Well? Which one is it? I'll take best guesses/best course of attack info please!

p3


Modified by phoenix_iii at 7:17 PM 3/11/2007

 

My first check would be the fan switch on the back of the block (if you have a sohc). What engine do u have? Also, buy OEM stuff, not cheapo aftermarket.

Also, how long have u owned the car? If not long, it could be possible that someone rigged it to constantly run.

 

Is your A/C or defrost on?

 

89DX. Stock everything. I found the proverbial little old lady. Nothing is rigged on the car. Everything is factory stock (had factory radio!)

The AC does not work, shrader (sp) valve leak according to paperwork, but heck, the button may be pressed but I don't think so. I will check that one Chimaira989. I will check for rigging too (bad mechanic maybe?), but shouldn't be. Driving tonight so I'll hit the AC button (Didn't want to press it!).

What's wrong with aftermarket for this kind of app? Neither should be too hard to install, and I wonder how much OEM would cost...

Will post back with results (and which fan it is that is on, left or right one).

p3

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by phoenix_iii &raquo;</TD></TR><TR><TD CLASS="quote">



What's wrong with aftermarket for this kind of app? Neither should be too hard to install, and I wonder how much OEM would cost...


</TD></TR></TABLE>

Thats just how i like to do it. Certain stuff i buy OEM only and these kinds of things fall under that category.

 

AC made a much different noise (tried it on highway with window open).

In the parking lot, fan comes on with key on... dummy didn't bring a flashlight to see exactly which one, but I would believe it safe to say it's the correct radiator cooling fan.

Electric Fan thermostat or Cooling Fan sensor?

Buy both and replace one, if workie, good, if not, install other part, if workie & cheap, install old part, if still workie, profit.

?

p3

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by phoenix_iii &raquo;</TD></TR><TR><TD CLASS="quote">

Electric Fan thermostat or Cooling Fan sensor?

</TD></TR></TABLE>

From what i can recall there's only one of those on our EF civics. Some people have different names for it but we dont have more than 1 sensor that tells the cooling fan to turn on (separate from the A/C system). Also, it should be the passenger side fan thats running on your car.

Try looking on the backside of the block and find the large sensor near the oil filter that has 2 wires going to it (sometimes there's a black boot covering it). Thats the fan switch. The single wire sensor is oil psi and is also located in the same area...so dont get them confused. Once you've found it, unplug either of the 2 wires and the fan should turn off. This is just 1 more step for troubleshooting.

 

I'll give that a shot this weekend early. I will go to the pick and pull and grab a fan switch and see if that's it if it's that easy to swap and test. Thank you fourthgenhatchB17, I'll post what happens.

 

Looks like both fans are running... as checked after work... wll review in a bit

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by phoenix_iii &raquo;</TD></TR><TR><TD CLASS="quote">Looks like both fans are running... as checked after work... wll review in a bit</TD></TR></TABLE>

Come to think of it, if the driver side fan is still hooked up, it will turn on whenever the other fan turns on and vice versa.

 

have you checked the wiring before you are looking at parts to be replaced?

 

Nothing looks jerry-rigged, if that's what you mean by checking the wiring LightWeightED8. fourthgenhatchB17, that's GOOD, I was starting to think something might have been up besides a worn out part. Still looking for what to replace. I saw that single wire sensor, so I think I know what to pull to 'pull the plug' on the fans. But that's the power for them, isn't it? That'd BETTER turn them off, hehe. Hopefully that's the sensor for it, and if they turn off, then we may have our bandit. I will give this a try maybe today after work in the parking lot. Thanks for being patient with me gents.

 

Its the fan switch thats on the back of the block. And yes it should turn them off when u pull the plug, lol.

 

Heh, so when I pull this guy out, and they go off, what does this prove? I guess if they stay on then there is some ghost power source (I assume the power for the fans also runs through the switch?).

If the power is seperate and they turn off, then we've found our bogey. Should I pull this fan switch while the car is running? I think it would be wise to do it while the car is off, no?

Thanks fourthgenhatchB17... will do this in the parking lot today before I head home... wish I wasn't wearing nice clothes for work.

 

Check out the relay and wiring testing procedure in the Helms manual. I'd test this stuff out before going and blindly replacing sensors. And in my experience at least a bad fan switch was associated with the fan not switching on. Just my $.02

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wiZCo &raquo;</TD></TR><TR><TD CLASS="quote">Check out the relay and wiring testing procedure in the Helms manual. I'd test this stuff out before going and blindly replacing sensors. And in my experience at least a bad fan switch was associated with the fan not switching on. Just my $.02</TD></TR></TABLE>

Ok and in my experience a bad relay causes the fan(s) to not run, so I would think the relay is good since the fans work! Wiring to them should be as well..again since they work! Its possible for there to be a wiring issue causing the fans to constantly be running but he claims its a non molested stock car so i would think that its highly unlikely. If there was evidence of wire tampering by the previous owner i would suspect something else. Im only offering my suggestions assuming the car is 100% untouched under the hood.

Phoenix: Yea id unplug with car off.

edit: Heres a tip, check for continuity between the 2 fan switch prongs with the engine cool. There shouldnt be any. If there is, bad fan switch! You will need a DVOM (volt/ohm meter) though.




Modified by fourthgenhatchB17 at 11:17 AM 3/1/2007

 

Trying to find the fan switch itself. Haynes has pic and says by lower radiator hose, but nothing I can really reach/see without jacking the car up. You said back of the block, as in towards the firewall? Can snap some pics with #s and tell me where to look? Hehe... sucks not having a garage. Can I get a little bit of a description as to where to look? i suck

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by phoenix_iii &raquo;</TD></TR><TR><TD CLASS="quote">Trying to find the fan switch itself. Haynes has pic and says by lower radiator hose, but nothing I can really reach/see. You said back of the block, as in towards the firewall? Can snap some pics with #s and tell me where to look? Hehe... sucks not having a garage.</TD></TR></TABLE>

Dude those manuals suck ***. Its on the back of the block and can be hard to locate if you've never seen where its located. Its about an inch or 2 away from the single wire oil psi sensor. When messing with that switch i feel my way around from the top. Do it when the motor is cool, lol.

No pics at this time, sorry. Maybe tomorrow if u can wait.

 

That's what I thought. It's facing the rear/towards the firewall, Is there something to depress (plastic latch?) to separate? Engine is cool I took the Monte to work today. I have an automatic trans if that makes any difference... I'll go pull on that guy now...


Modified by phoenix_iii at 6:55 PM 3/1/2007

 

Nope just pull the black plastic sheathing off then you see the 2 slip on
connectors...

EDIT: Ohhhh no 2 fourth gens haha!!

 

Heh I finally grew a brain and read engine BLOCK. YEah found what I believe is it. Has two 'hard'ish wires coming out of what looks like a little black bell/teepee housing. Tough to reach, especially in a nice button down shirt, and wanted to verify this was correct. However, reading in the Haynes I'm 90% sure it said disconnect and the fans should come ON... It's possible for the switch to be defective and they are on all the time, right, like it's not doing it's job to 'close' and turn them off? Because if that's the case then we pretty much know it's not doing it's job, because when I pull it out, they will still be on... *need* a new one/replacement known good to test. Nothing looks likes it ever been touched under the hood.

Tips/tricks for access (is putting the car up and getting it from under, better? Was going to do an oil change this weekend or next weekend anyway...

Thanks for help!

p3

 

Sounds like you're on the right on track but when u unplug it i can almost gaurantee they will turn off. Its when u unplug them and connect the 2 wires together is when they'll stay on.

 

Heh maybe THAT'S what I read. Alright, so that boot just slides off/down the wires? and then literally pull on the wires? They seem pretty firm, as in rigid, not like normal wires? Anything to worry about?

p3

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by phoenix_iii &raquo;</TD></TR><TR><TD CLASS="quote">Heh, so when I pull this guy out, and they go off, what does this prove? </TD></TR></TABLE>

It will prove that the switch is keeping the fans on or not.
IF you pull that out (make sure its the one with two wires dude) and the fan is still running, it may be jerry rigged after all. I used to jerry rig my fan all the time when i did not have enough time to replace the fan switch ( which turns the fan on) and did not want to overheat.
The switch does not provide the power to the fan it simply decides when the fan should go on. It pulls the relay that is connected to the fan.

 

if you need an extra switch i have one for free. just paypal me $1 for postage.
IM a shipping address and i will put it in the mail box tomorrow you can paypal me the $1 later. Regarding the relay i once had a relay crap out on me in the on position for like day. Anything is possible....