Fresh Air Blower

[Jonny Hart]

Hi,

 

Got fed up with the horrendous noise when fresh air blower operated. Took it all apart - easy fix - new motor not required, just some oil.

 

Here's how (on an SC anyhow):

 

Firstly, take out the luggage space carpet and remove the fibre board panel to reveal the blower:

 

 

Loosen the three duct jubilee clips and wiggle off. Remove the electrical plug at the bottom and disconnect this cable:

 

 

Then, there are just two 8mm bolts holding the blower to the car. Remove them and take the blower to the bench.

 

Locate and disconnect the two power cables from the motor and hook up to car battery to test (brown is negative). Hopefully, the motor will run with no sparks. Mine ran but once up to speed, started making the horrible noise. Check the motor brushes - again, mine were fine. If you get this far you probably just need to oil the motor shaft, so here's how:

 

Undo the three self tappers that hold the additional ducting piece on - remove.

 

Then take off the spring clips (six total):

 

 

Now you can split the casing, to get at the motor:

 

 

Turn the motor over and locate this hole.

 

 

Turn the fan round until the hole lines up with the oil hole in the motor and lubricate. You can now run the motor and check that the noise has stopped (watch your fingers if running it out of the case).

 

Refit to the case. The spring clips are annoying to get back on and want to fly (most irritating part of the job)

 

I then spotted the cap in the centre of the motor:

 

 

Removed it:

 

 

And shoved some oil down there as well.

 

Motor is now silent.

 

Don't know how long this will last but worth a shot. Took about an hour to do in total.

[Phill]

(watch your fingers if running it out of the case).

 

Have you still got all yours?

 

 

Another top tip, keep 'em coming mate.

[theo5042]

Top write up.

[Jonny Hart]

Have you still got all yours?

 

Fingers all present - just a bit shorter than before.

[Dr Rock]

Just did this yesterday/today. Took about 2hrs max. Job is the same on a 3.2. Those clips are the hardest part. Taking them off I used a jewellers screwdriver to prise them off: watch they don't ping into outer space and mind your eyes...

[alanchester]

Love this type of job, so satisfying and cost hee haw to do!

[longman]

can you do a Jonny fixes heat workshop at yours ? , my footwells dont blow.....

[Jonny Hart]

can you do a Jonny fixes heat workshop at yours ? , my footwells dont blow.....

 

I bought some shagged 3.2 blowers off RB. The motors had seized but I wanted the ducting. In the end though I fitted a pair of these

 

 

 

http://www.t7design.co.uk/index.php?main_page=product_info&cPath=87&products_id=235

[Jonny Hart]

Second thoughts, lend me your car over Christmas and I'll fix them for ya

[OzSC]

I bought some shagged 3.2 blowers off RB. The motors had seized but I wanted the ducting. In the end though I fitted a pair of these

 

 

 

http://www.t7design.co.uk/index.php?main_page=product_info&cPath=87&products_id=235

 

Hi Jonny. I'd been wondering about fan replacements. When you say you fitted a pair, can you let us know where you fitted them etc.

Cheers

Ian

 

 

Sent from my iPad using Tapatalk HD

[Jonny Hart]

 

Hi Jonny. I'd been wondering about fan replacements. When you say you fitted a pair, can you let us know where you fitted them etc.

Cheers

Ian

 

 

Sent from my iPad using Tapatalk HD

 

 

Like this:

 

 

(the one shown has my expirimental PTC heater sandwiched in it, hence the thick wires - you'd just connect the thin fan wires)

[OzSC]

 

Like this: (the one shown has my expirimental PTC heater sandwiched in it, hence the thick wires - you'd just connect the thin fan wires)

 

Thanks. "experimental PTC heater"... I'm intrigued. Did the experiment work?

Edited December 11, 2012 by OzSC

[Jonny Hart]

Now it's getting cold (in thr UK anyway) a number of people have contacted me about this so ill start a new thread I think.

[felix83]

Thanks for this guide, tried it today as a 'whilst in there' type project when replacing the intermittent wiper relay. I too used a small screwdriver to pry off most of the clips and in some cases some narrow pliers. Holding a finger on the plastic 'knob' the clips attach to prevent them from going airborne. Reattaching the clips and refitting the blower assembly in the car were the fiddly bits. But everything came together in the end and now I'm a happy bunny as I've got both a quiet blower as well as wipers parking where they should.

[BenC]

great write up Jonny,

 

blower motor in my 3.2 was beyond fixing so fitted a new one today (approx £72 delivered.)

http://www.design911.co.uk/fu/prod4690/Heater-motor-Porsche-911-1965-89/

- very helpful to have read through your post before hand.

 

I managed to leave most of the bits still in the car rather than remove to the bench

 

 

 

quite surprised how loud the new motor is, even though it was silent when I was spinning the fan by hand.

going to run it for a few weeks and see if it beds in, if not I might have to take it apart again and get some oily grease into it should be much quicker to dis-assemble second time around

 

 

ps - found a three way connector on the tube that carries the intensive wash - odd to have one part open and I can't see a loose tube so think I'll swap it out for an inline connection

 

 

[supersport]

After a bit of contorting I got the assembly out of the car, only a little back ache, and split apart quite nicely. I have broken it down as far as I can go but, how do I get the motor off of the fanblades?

 

It doesn't go round very smoothly and I kept getting a burning smell until I turned the fan off, so I think the motor has had it. I can't believe how dirty the thing was inside,

[BenC]

The white plastic 'drum' part of the fan is a friction fit onto the smooth silver spline of the motor.

I filed around the 6mm that protruded to make it slightly smaller in diameter then it pushed off (with a bit of force)

 

To fit the new one I drove it on with light taps from a hammer, then hit a socket head over the spline to make sure it protruded.

 

Hope that helps

[Fuchs915]

As my blower was siliconed to the air box behind, had to take it all out this evening

 

 

Looking down the end of the twin bit attached to right hand side in above picture, when the valve flap is moved to open the left channel, is this how it should look, ie square with part of the tube left open? Looks like it had something glued on, so wondered whether it should have a soft (rubber, fabric, etc) flap.

 

 

Thanks

 

Kevin

Edited July 22, 2013 by Fuchs915

[supersport]

After a bit of contorting I got the assembly out of the car, only a little back ache, and split apart quite nicely. I have broken it down as far as I can go but, how do I get the motor off of the fanblades?

 

It doesn't go round very smoothly and I kept getting a burning smell until I turned the fan off, so I think the motor has had it. I can't believe how dirty the thing was inside,

So it looks like it's hammer time. Thought it might be :-)

[BenC]

Think so - there was a squashy foam section stuck over the flap bit.

 

Going to take mine apart again soon to oil it so will try and take some pics to show

[Fuchs915]

I think you are right. Just found a bit of foam inside it, which crumbled to dust when I touched it. If you can get a pic of what it should look like, that would be great and I can try to recreate it.

 

Thanks

 

Kevin

 

[supersport]

Got all apart with a little pursuasion and ordered a new motor. It was £13 cheaper from here though https://sslrelay.com/type911shop.co.uk/shop/article_841/911-1970-89-Fresh-Air-Fan-Motor.html?sessid=gRZ0loI8L6Gu4bruTarUYaF6kFukXMlLcKwTaM227SDOBVII7PiK659rM0txU0JW&shop_param=cid%3D323%26aid%3D841%26 but still about £74 delivered rather than £89 at the link above.

 

The whole thing was rather dirty so it was nice to give it a good clean out and looking forward to having a working blower again, assuming it all goes back together as easily.

[BenC]

I suggest that you put plenty of oil into the new motor when you fit it - was quite surprised how loud the new motor is that I fitted the other day, to the point that I'll be taking it back out to oil it soon!

[The Colonel]

My fresh air blower worked but made a painful squeal when starting and stopping, I could live with that.

 

This weekend it stopped working completely and I have the burning smell, so it's time to do something about it.

 

Reading the related threads it could be the motor or the 'bi-metallic' switch.

 

Can someone tell me where the switch is in relation to the blower motor and if it is possible to do a simple test on that switch ? I'm going to take the blower motor out to clean it up anyway even if it is the switch.

 

Thanks for the great pics and advice on this thread.

[Dr Rock]

Can someone tell me where the switch is in relation to the blower motor and if it is possible to do a simple test on that switch ?

IIRC it's in the blower housing.