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Cooling fans for NB8C or SE

Posted: Mon Nov 13, 2006 7:45 pm
by ASE05
At the last track day I came in after my 1st session and the temp was past hot :shock:

After freaking out and not finding any coolant leaks I traced it back to the 30A fuse blown for the fans. I've since replaced the fuse and all seems well except that only the fan on the passenger side is blowing. Is the fan on the drivers side for the air-con? I've left it idle for a bit but still only 1 fan......

Are both meant to go for normal cooling or just the one?

Posted: Mon Nov 13, 2006 7:48 pm
by Fatty
in the NA, one of the fans only comes on when the aircon is switched on. the other runs all the time (well, when it's needed)
i'm guessing your NB is the same.
flyin miata recommend that if you have a turbo fitted, you should wire the fans in parralel so that they both come on when things get hot.

Posted: Mon Nov 13, 2006 7:49 pm
by Babalouie
Easy enuff to find out....turn on the aircon and see if the other fan comes on :D

But fans only help low speed cooling, so if you're running hot at track speeds you have other issues. Do you have all the stock shrouding on top and below the radiator? You know, the prevent the air from going around the radiator instead of thru it....also what's the colour of your coolant, you may have a blocked rad, which is pretty cheap to have cleaned out professionally (I think I paid $130).

If the rad is partially blocked, then sections of it won't be as hot to the touch as others. Do you have your number plate mounted such that it blocks off part of the grill mouth?

Re:

Posted: Mon Nov 13, 2006 7:56 pm
by ASE05
Babalouie wrote:Easy enuff to find out....turn on the aircon and see if the other fan comes on :D

But fans only help low speed cooling, so if you're running hot at track speeds you have other issues. Do you have all the stock shrouding on top and below the radiator? You know, the prevent the air from going around the radiator instead of thru it....also what's the colour of your coolant, you may have a blocked rad, which is pretty cheap to have cleaned out professionally (I think I paid $130).

If the rad is partially blocked, then sections of it won't be as hot to the touch as others. Do you have your number plate mounted such that it blocks off part of the grill mouth?


hahaha t you babs :mrgreen:

No cooling probs on the last 6 track days.......untill the fuse blew! No cooling probs now but I just wasn't sure if both fans were for the rad or if one was for the air. I've left it running with the air on though but still no 2nd fan, hmmmmmm............I think I may have just discovered why my aircon sucks at idle :idea:

Posted: Tue Nov 14, 2006 7:33 am
by Marty
I had a similar problem when I first got my car. It turned out to be a faulty earth connection - fixed under warranty so unfortunately don't know exactly what was wrong.

Posted: Tue Nov 14, 2006 8:29 am
by Garry
The driver's side fan should switch on and off with the A/C compressor.

Posted: Tue Nov 14, 2006 8:43 am
by Okibi
Look in the Garage section of Miata net, there's a few pages on how to wire them both up to work (without aircon on).

Or just upgrade to an aftermarket ECU that can control the fans and give you even more power :twisted:

Re: Cooling fans for NB8C or SE

Posted: Tue Nov 14, 2006 7:51 pm
by blackster
ASE05 wrote:
Are both meant to go for normal cooling or just the one?


On the SE, after the engine has reached operating temperature both fans come on intermittently & simultaneously; thats not with the air con on.

Re: Cooling fans for NB8C or SE

Posted: Tue Nov 14, 2006 8:25 pm
by ASE05
blackster wrote: On the SE, after the engine has reached operating temperature both fans come on intermittently & simultaneously; thats not with the air con on.


I'm assuming this is what yours does Blackster.....both fans come on together even when the air is off?

I reckon that's what you're saying but just wanna confirm.

What does everyon reckon my chances are of getting Mazda to sort it under waranty given the mods I have done? I reckon fook all but the mods aren't the reason for the failure......

Re: Cooling fans for NB8C or SE

Posted: Tue Nov 14, 2006 9:11 pm
by blackster
ASE05 wrote:
I'm assuming this is what yours does Blackster.....both fans come on together even when the air is off?

I reckon that's what you're saying but just wanna confirm.


Correct, im happy to take a short mpeg to show you when there's a bit of daylight.

What does everyon reckon my chances are of getting Mazda to sort it under waranty given the mods I have done? I reckon fook all but the mods aren't the reason for the failure......


You got nothing to loose, I guess it comes down to what kind of relationship you got with your service manager. If he is by the book, he could say that that your mods have caused the problem and then its upto you to prove otherwise to mazda australia that its not, if you want to pursue it under warranty.

Have you got someone else to have a look at it? It could be a simple cheap fix if the fan motor hasnt burnt out.