# Disassembly of Fan Blower Motor Unit



## darrylmg (Oct 16, 2021)

I'm a firm believer of trying my best to work out why the heck something is broken.

Back in November 2021 my fan blower stopped working.
I temporarily fixed it by removing it and spraying with contact cleaner into the motor area. I imagined it was the motor brushes or some other issue somewhere.
I also removed and cleaned the resister PCB but this was spotless and showed no issues.

Blindly spraying fixed it... .... until November 2022 (coincidence ? ).
Initially I thought, ha, I'll take the fan blower out, spray it with contact cleaner again and I'll be good for another year.
Yes, it did fix it again, but this time only for one week. Boo!
After some fiasco with Autodoc and the Royal Mail being on strike and causing delivery chaos, I bought a replacement fan blower from GSF Car Parts (they had a 65% sale luckily) where I could go and collect it.
After fitting the new fan blower, the car was back in action again. Yay!

Now was the time to take the broken one apart.
It was an original part made by Valeo.

It had rust on the spindle and an extra weird metal clip on one of the fins (maybe to balance it?):










The motor unit removes from the exterior housing using some leverage (big screwdriver).
It is only slotted into the cutouts and actually only held in place with three rubber lugs that provide a bit of resistance.
Right at the bottom of the exterior housing you can see a bit of moisture build-up. This probably doesn't help the longevity of the fan motor, it lives it's life upside down like this and any moisture would just pool at the bottom, then on warm days evaporate up past the motor. 
You can also see one of the two spring loaded brushes.










The plastic casing around the motor is not held in by anything, but it doesn't easily slide off.
I ended up just breaking it apart to expose the motor itself.












It's a Bosch motor.
2x contact brushes (one either side) and 2x large magnets (this is not a 2 phase motor).
The motor is not easily disassembled without breaking into the metal shell.










The copper contacts on the spindle were all scored from the brushes:










The brushes were also scored, but looks to be plenty of contact and lots of material left.
It's possible they were just contaminated on the outer contact point and probably could have benefited from a really good wipe off:










This rusty end of the spindle does not affect the operation of the motor.
Below this point is a bearing and mine was nice and clean.
So ignore the rust on this part and also the other end (the end you can see in the first picture).











Summary:

Not really possible to fix any real issues with this motor because it's almost impossible to disassemble cleanly.
I suspect the contact points of the brushes with the spindle could be dirty and need wiping. Maybe that is why contact cleaner seems to work some of the time.
I've seen a youtube vid of a guy soaking this whole unit in a bath of contact cleaner. This is probably the only way to really clean it up.
£300 - £400 for an OEM part from Audi is not worth it!


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## Beryl (3 mo ago)

Would it be possible to run it off a battery and get some more cleaner into the motor with it running?On the face of it, looks like it not on its last legs. Anyways good there are alternatives about for a lot less than £400!


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## Steviejones133 (Aug 18, 2021)

Top write up again as usual 👍🏻

Im thinking that these motors often fail due to moisture in and around them over many years. The location of them is - fro what I understand - quite prone to being in the vacinity of water leaks or maybe even water entering the heater system via the HVAC inlet under the plenum.

Theres no way I’d pay Audi £400 for a bit of plastic and a small motor, I’d even be tempted to try and find a used one of fleabay or a local scrapyard first but if you got a new one cheap, I guess that’s the way to go…..

Hope it’s golden for you now it’s spanking new, shouldn’t have any more issues during the cars life now 😆


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## SwissJetPilot (Apr 27, 2014)

Great write up! 

It would be very interesting to know how to remove and replace the bearings, if that's possible. Might require some additional digging through Bosch catalogs and websites to figure out what parts they are using.

Can you provide a zoom photo of the data stamped into the case along with any other data that might be marked somewhere else. The PN looks like 0 130 101 627...?









I did find this Bosche catalog which has a motor that looks very similar. Unfortunately I didn't see any replacement bearings listed. Bosch may not have designed these to be rebuilt. But it doesn't mean they can't be if you can get the bearings out and find a suitable replacement.


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## darrylmg (Oct 16, 2021)

SwissJetPilot said:


> Great write up!
> 
> It would be very interesting to know how to remove and replace the bearings, if that's possible. Might require some additional digging through Bosch catalogs and websites to figure out what parts they are using.
> 
> ...


Yeah I'll post a better pic of the part numbers. 
With a lot of patience, grease and more patience you could possibly get the motor out without breaking anything, but from what I found, it's not an easy job. Very frustrating. 
The bearings are unserviceable though. The motor casing is put together and then blunt force is used to mesh the component parts of it together.


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## darrylmg (Oct 16, 2021)

Beryl said:


> Would it be possible to run it off a battery and get some more cleaner into the motor with it running?On the face of it, looks like it not on its last legs. Anyways good there are alternatives about for a lot less than £400!


Quit possibly. 
A small cotton bud (q-tip) might reach the spindle, but otherwise you can't really get access to the electrical parts.
A contact cleaner bath sounds the best.


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## zsdom (Oct 25, 2020)

Did you lubricate with grease after the contact cleaner?

If not it possibly seized back up with the lack of lubrication


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## SwissJetPilot (Apr 27, 2014)

Okay, so replacing the bearings isn't an option. Looking at the photos, I was afraid that might be the case.


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## darrylmg (Oct 16, 2021)

zsdom said:


> Did you lubricate with grease after the contact cleaner?
> 
> If not it possibly seized back up with the lack of lubrication


It wasn't seized. I could spin the fan blades with no problems. It just decided to not turn on.
Sprayed with contact cleaner around the motor and it would work again, for a while.


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## Jezzie (May 24, 2020)

While the carbon brushes seem to have some length to them, do you think they were making good contact with the commutator? If may be they need to be replaced. It’s amazing when replacement brushes arrive to see how long they were originally!
For example, these are 22mm long:





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## chestnutree (Jun 4, 2012)

Interesting to read this just after discovering mine had failed. Also adds up in my case - Battling with water ingress so the car is very damp. You mention how moisture can sit in the bottom so this has more than likely caused the rusting in my case siezure. I'm pretty sure the fan hasn't failed completely as the lights dim and the revs increase slightly when I attempt to turn the blower speed on/up but it's just not blowing. Hoping the clean/grease will sort mine out from the help given on my post when i attempt it at the weekend.


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## Beryl (3 mo ago)

Pulled mine out. Built 11/07. No play and sadly, nothing but a bit of leaf to account for the various tinkling sounds when fiddling with the controls once warmed up. Also no retaining bolt, just a plastic tag to hold its position. I’ve changed the pollen filter. Is there anything else worth investigating in this area Before popping the glove box back? Thanks.


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## SwissJetPilot (Apr 27, 2014)

Beryl said:


> Is there anything else worth investigating in this area Before popping the glove box back?


No, not really. If your HVAC vents are all working like they should, there's not much else back here.


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## darrylmg (Oct 16, 2021)

Beryl said:


> Pulled mine out. Built 11/07. No play and sadly, nothing but a bit of leaf to account for the various tinkling sounds when fiddling with the controls once warmed up. Also no retaining bolt, just a plastic tag to hold its position. I’ve changed the pollen filter. Is there anything else worth investigating in this area Before popping the glove box back? Thanks.


Put your hand up inside where the fan goes and pull out the debris.
Same goes for the pipe that leads into the car blowers. I got a few bits of leaf out of mine and a very dirty hand


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## darrylmg (Oct 16, 2021)

SwissJetPilot said:


> Great write up!
> 
> It would be very interesting to know how to remove and replace the bearings, if that's possible. Might require some additional digging through Bosch catalogs and websites to figure out what parts they are using.
> 
> ...


Better pic of the part numbers:


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## darrylmg (Oct 16, 2021)

Jezzie said:


> While the carbon brushes seem to have some length to them, do you think they were making good contact with the commutator? If may be they need to be replaced. It’s amazing when replacement brushes arrive to see how long they were originally!
> For example, these are 22mm long:
> 
> 
> ...


Difficult to say. They are quite scored as you can see, so I don't know how much that would affect things.
They are spring loaded. I guess it is possible over time for the spring to lose its fighting force.

Something that might help diagnosis:
- both times my fan stopped working completely was in November. It was cold. I really couldn't drive the car without the fan because of steaming on the windscreen due to the temperature outside (well, I could drive with the windows open, but I'm not a flippin Eskimo, it was cold).
When I decided enough was enough it was really really cold out.

I wonder if the contact from the brushes was minimal or dirty and the metal shrinkage from the cold was enough to break contact... maybe.


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## Jezzie (May 24, 2020)

The maximum extension of the spring is limited by the length of the copper braid that connects the brush to the connector. IMHO it’s more than likely new brushes would solve it.


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## darrylmg (Oct 16, 2021)

Jezzie said:


> The maximum extension of the spring is limited by the length of the copper braid that connects the brush to the connector. IMHO it’s more than likely new brushes would solve it.


The new one is a different design.
Hopefully it will be serviceable but I doubt I'll need to touch it in the next 10 years (hopefully).
Might need to invest in a good boat by then judging by the amount of rain we've been having.


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## TT'sRevenge (Feb 28, 2021)

The clip(s) is indeed there to balance the assembly so it stays smooth at all operating RPMs.

10 years is really not that bad (IMO) for something that is basically _always_ in operation whenever the car is on--it only shuts off if you turn the climate control fully off by rotating the centre knob to the OFF position--most owners will almost never do this and in AUTO mode, the fan will always be on even if it's on the minimum setting.

It doesn't seem like the brushes are easily replaced as you need to destroy things to get in there 

As you pointed out, this is not a 2-phase DC motor but II wonder if any newer or higher end cars use brushless drive motors on the blower fan?


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