Air Con Condenser Fans - Air Flow Direction

[wixer]

Hi All,
I've just rebuilt my air-con condenser assys, including replacing the fan motors with some non NSX parts (Honda Goldwing radiator motors). Although there are arrows on the NSX actual fan blade mouldings & I've wired the motors to rotate in this direction I'm dubious, now I've tested the assys, that they are rotating in the correct direction.

The reason for my doubt is, when the fans are in operation, they are blowing air through the condensers, i.e. from wheel side to bumper side.

As they have never worked since I've owned the car, I don't know if this is correct. I would have thought they would pull air through the condensers, so work in conjunction with the natural ram effect of air flow, when the car is being driven ?

Or do they only really ever switch on when the car is stationary, as the ram effect of air movement is sufficient to cool them, other than when the car is stationary ?

Cheers for any enlightenment.

Wix

[britlude]

air should be drawn thru the air con rads and expelled through the wheel well...

[Kaz-kzukNA1]

As britlude mentioned and as same as the Rad fan, the air enters from the front and exits towards the rear of the car.

As it states, it 'condenses' the high pressure/temperature gas state refrigerant into liquid state by sudden heat dissipation so efficiency is the key.

The R & L condenser fan motors are always active whenever the CFCU (Cooling Fan Control Unit) engages the condenser fan relay.

Check pinout on the non-NSX fan motor and probably you will need reversing it.

Kaz

[wixer]

Thanks Jon, Kaz, for the replies, you've confirmed my thoughts. I'll adjust the wiring polarity and get them to 'suck' rather than 'blow'. Fortunately, I've yet to put the bumper back on, so everything easily accessible.

Cheers.

[Kaz-kzukNA1]

If you have a chance, it would be nice if you can take a photo of the non-NSX rad fan mounted at the back of the NSX condensor.
Was it cheaper than the NSX spec motor?
Was it direct fit or lots/minimum modifications required?

I'm quite sure it will become handy as from time to time, this motor can seize and the replacement is not cheap.
Some owners did overhaul/refurbished the seized motor but if replacement available at reasonable price, that will add another option.

Kaz

[wixer]

If you have a chance, it would be nice if you can take a photo of the non-NSX rad fan mounted at the back of the NSX condensor.
Was it cheaper than the NSX spec motor?
Was it direct fit or lots/minimum modifications required?

I'm quite sure it will become handy as from time to time, this motor can seize and the replacement is not cheap.
Some owners did overhaul/refurbished the seized motor but if replacement available at reasonable price, that will add another option.

Kaz

Yes, no probs. There are some pics on my re-build thread but I didn't go into detail about the motors there.

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The two motors I sourced were from Honda Goldwing motor bike. From Ebay £40 for the pair. I'd looked at various other motors, mainly from other Honda vehicles but the problem was always the motor body diameter, was too large as a replacement for the NSX motors, so they wouldn't have fitted in the hole in the rear plastic mounting/shroud. They are the same make as the NSX motors though, so in terms of durability, hopefully they should be up to the job. Time will tell but even if they have to be replaced every few years, they're a lot cheaper than OEM (about £150 each from Amayama).

There is a difference in the length of the main bodies but some of that is the fish-eye effect on the photo. The only thing I had to do, was buy some small plastic spacers, which were only a few £'s, to mount the Goldwing motors closer to the condensers, circa 15mm, the differences between the mounting faces, can be seen on the photo. Other than that, they dropped straight in, the body diameters being almost the same. The only thing then to do, was swap the connectors over but as the previous posts highlight, I need to reverse the polarity to get the fans to suck instead of blow. I have yet to re-fit the wheel arch liners but I don't see any issues there.

[Kaz-kzukNA1]

Hi, Wix.
Thank you for the extra info and the photo.

Don't know the spec of the motor but since it's for the rad fan, should be enough flow rate.
You'll know when measuring the pressure on a hot summer day.
Should become handy for other owners in the future.

Had a quick look at your build thread as well.
Since you have disturbed the a/c system and replacing the condensers using new/used parts, best flushing the system while you have extra space.
And seal it unless you are evacuating the system immediately afterwards.
As it's off topic from this thread, I won't go into detail.

Kaz

[NSXGB]

The earlier car engine bay fan looked like it would fit and do the job...

[wixer]

The earlier car engine bay fan looked like it would fit and do the job...

Yes, it was our discussion that set me off on what else would fit. Problem with the engine bay motor, is trying to find one/two for a reasonable price, as they have the NSX tax associated, as do secondhand condenser motors. The odd one I could find, had asking prices not far off the cost of brand new OEM ones from Amayama.

[wixer]

Hi, Wix.
Thank you for the extra info and the photo.

Don't know the spec of the motor but since it's for the rad fan, should be enough flow rate.
You'll know when measuring the pressure on a hot summer day.
Should become handy for other owners in the future.

Had a quick look at your build thread as well.
Since you have disturbed the a/c system and replacing the condensers using new/used parts, best flushing the system while you have extra space.
And seal it unless you are evacuating the system immediately afterwards.
As it's off topic from this thread, I won't go into detail.

Kaz

Kaz, when everything is back together I'm taking the car to Bee Cool in Kettering. A few members have been there, so I spoke to them last week. They've very helpful & they have recommended I get the system refilled with a refrigerant called RS24, which is a direct replacement to R12, rather than go down the R134 conversion route. I'll let them do all they need to do in flushing and re-pressurizing the system.

It looks like the system hasn't worked in many years, so until this work is under taken, I won't know what other things may be faulty. Hopefully nothing.