Intermittent heater blower fault

Posted: Wed Nov 14, 2007 8:54 am

Typical - now's the time of year when heat is an essential, and the blower packs up! Evil or Very Mad

1996 A4 Avant B5 - SE model, with digital heater controls as opposed to the rotary controls (formerly aircon, now U/S and disconnected - not related)
Heater works fine (as in, throws out heat...) - BUT, it's the actual blower that doesn't work. Fault was intermittent initially, but now doesn't work at all. Display works fine, shows blower speed increasing, all direction controls work fine (I can hear them) as does 'defrost' control - but just no blower, so heat is only felt when the car is actually 'at speed' and hence forced into the cabin.
I've checked the fuse (OK) and am assuming it's a connection/cracked wiring fault. Any idea where the blower is??! Any suggestions please?

Cheers,
Alan Very Happy

Posted: Wed Nov 14, 2007 11:15 am

Hi Al.
Right, my guess is, at your milage now the motor brushes have failed in the fan. If you've not been fiddling with the cars wiring I doubt it's a wiring fault.
First off, you need to get in there...

(Thanks to another forum for the pic)

Just remove the side panel and it's 5 x 10mm bolts. Remember to unplug the light before pulling completely away, and when refitting the back piece slides into a slot, so ensure this is engaged before pushing all the way up & in.
Just unplug it and remove the 3 screws and the whole thing pulls out. You will have to remove the big bracket in front of it to give you enough room to manoevour it out though.

You have 3 options as I see it Al...

(1). There is a way to make the brushes last a bit longer. You will notice that the way the brushes are pushed in that the spring limits how far they can go down by putting tension on the wire part of it, if you fiddle the wire part of the brush into the spring it lets the brushes sink down another couple of mm, should last a few more thousand miles doing that.

(2). You can try to source some new brushes like These

(3). New unit. Don't bother with second hand or you'll just end up with same problem. I don't like quoting part numbers but pretty sure you need 8D2 820 021. Eurocar parts quote about £99 + vat for Valeo OEM, Stealers about £370 Shocked

or try good old ebay like This one.
Hope this helps matey.
The only other thing that goes wrong with these is that water gets into them down through the pollen filter due to badly fitted scuttle and seizes motor but this usually blows the fuse.
Good luck.
Si.

Posted: Wed Nov 14, 2007 7:49 pm

Thanks very much Si - top marks for that lot Very Happy

Sods Law - bloody thing worked this morning, but chose not too tonight Evil or Very Mad

Must be a bloody female in their controlling those motor brushes..... Confused

It'll have to wait until the weekend, but at least I now know where to look and what to expect.

Thanks again Si. Till later....

Alan Very Happy

Posted: Sat Nov 17, 2007 4:03 pm

Sorted

Following Si's excellent advice, I removed the blower motor and pulled the actual motor from its mounting; removed both brushes (well worn Confused

) and s t r e t c h e d the springs a little; pushed both back in, reassembled and Bob's your mother's brother Laughing

New brushes on order - again as per Si's advice - so will have these fitted soon.

Cheers guys - and especially to the helmsman of 'The Barge' Wink

Alan

Posted: Sat Nov 17, 2007 7:03 pm

Nice one Al, I'm just happy to have got it right for ya Cool

Where did you find the new brushes? Just so it's here for the future Wink

Si. (Off for another chug up the canal)

Newbie Joined: Dec 02, 2007 Posts: 15

He got them from ebay

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=190177135801&ssPageName=STRK:MESO:IT&ih=009

Alan - glad you got it sorted. I had the same problem on my Passat and its a nightmare not having a heater at this time of year.

Replacing the brushes really isn't a hard job and can save you about £400 over main dealer prices

(hope my sigs not too big - if it is mods feel free to remove it Very Happy

)

Inexperienced Joined: Nov 06, 2006 Posts: 27

All,

Just wondering if anyone has the dimensions for new brushes on a 1999 A6 4.2 Quattro. My father in law is an ex mechanic and has a contact who can get some made to order as it were just need to know the dimensions for new brushes.

Cheers.

Posted: Thu Dec 06, 2007 9:23 am

Something Audi related would be alot nicer Wink

Newbie Joined: Jul 15, 2005 Posts: 8

Similar story on my A6...

Without any warning noises, heater fan in Climate Control setup seems to have died. LED bars on display indicate fan speed increasing - choosing airflowdirection buttons I can hear 'flaps' moving - but no airflow at all.

Can any authorities out there advise if brushes or blower unit is the likely problem? Part numbers ? Sources? getting access to Heater?

Audi A6 2.4 SE

cheers

Newbie Joined: Dec 02, 2007 Posts: 15

sounds like it could well be the brushes. keep trying it over the next few days as it may start working again as and when it feels like it.

Brushes are available on ebay for Passat and A4 so the blower motor could well be the same.
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=190184576444&ssPageName=STRK:MESO:IT&ih=009

I'm not too sure about the A6 but on the A4 and Passat the blower motor is located behind the glove box. Its held in by 3 screws and its really not hard to get it out and change the brushes.

Can get access to the blower motor and check the part number or measure the brushes

Posted: Sat Dec 29, 2007 9:42 am

I'll agree with Baz - sounds very much like the brushes.

I finally got round to replacing mine yesterday (the earlier temporary stretching of the springs kept it going until I found time and a brief dry spell). Half an hour and the job was done, following Si's excellent advice earlier in the thread; you will need a soldering iron, but no special skills - perhaps just as well as far as I am concerned Confused

I got my brushes from Barrie Stewart via the eBay link - top gear, top service.
But - not sure if the A6 is same or similar?

HTH,
Alan Very Happy

Posted: Sat Dec 29, 2007 12:37 pm

Simple things first!...Have you checked the fuse??
Si.

Newbie Joined: Dec 02, 2007 Posts: 15

You can fit new brushes without a soldering iron.

What you need to do is
1 - pull the old brush out but leave the copper wire connected
2 - file the end of the old brush flat (the brushes file very easily as the copper compound is fairly soft)
3 - snip the copper wire end off the new brush and then file this end so that it is also flat
4 - insert the new brush into the motor (tapered end first)
5 - insert the old brush into the motor and replace the spring and cover

I done this with my Passat and it worker perfectly. Filing the ends of the brushes just ensures that both surfaces are flat and have good contact between them. I have attached a very simple diagram to show what I mean above.

Posted: Wed Jan 09, 2008 9:31 am

1st of all a big thanks to all of you above, I had the same problem with my heater blower on my '98 audi a4 avant 1.9tdi (130,000m). To solve the problem (all be it a temporary fix ) I swaped the retaining springs for the brushes with stiffer springs until I can find some replacement brushes. Anyone know where I can get some from? Ive tried ebay (including the link provided) and various other sites but no luck. My other option is to make/modify some. We machine alot of graphite grade d17/d15 where I work does anybody know if this would be a suitable material to use ?????? Im gonna try it anyway and I'll let you know how it works (there could be a gap in the market here!!! ) Thanks again, It was a pleasure to drive to work this morning with a clear screen and without coat, hat, gloves,scarf and a hot water bottle!

davow

Posted: Wed Jan 09, 2008 11:03 am

Email the eBay seller Barrie Stewart - barriestewart(at)tiscali.co.uk - he's a very helpful chap and will let you know when he's likely to get some more brushes.
In the meantime, I'm sure your temporary fix will keep you warm!

HTH,
Alan Very Happy

Posted: Wed Jan 09, 2008 11:35 am

cheers Alan,
Ive just sent him an email, also made some from graphite which I'll fit tonight ! (will let you know if they work/last!) cant wait to put my dash back together, the jangling of screws, brackets, spanners etc in the footwell is almost as annoying as having no heater! davow

Posted: Thu Jan 10, 2008 12:05 pm

Im making some brushes for my 98 a4 avant. the dimensions are 8mm x9mm as for the length, the pocket depth is 22 mm. The springs maximum compresion is 5mm so I would make them 16mm long and then file a 45 degree chamfer on them ( make sure its the correct way as they are not square, the chamfer should cut across the 8mm dimension) I would give you a diagram if I could but I dont know how! Ive actually made mine slightly shorter as Im keeping some of the original brush placed behind the new brush so I do not have to re solder ( there is approx 4mm left of the original which I have filed flat ie Ive made mine 12mm long. Ive made them out of d17 grade graphite which works fine. Alternately you could probably use any brush 8mm x9mm and modify it to suit. The material is very soft you can easily size it with some wet and dry. Hope this helps. If this all sounds like too much of a pain in the arse, the chap from ebay will be listing some more brushes soon so keep an eye on him, theres a link to the item in the thread.

Newbie Joined: Dec 02, 2007 Posts: 15

In response to daves post above "Alternately you could probably use any brush 8mm x9mm and modify it to suit" if you use the wrong grade of carbon for the brushes then you may get problems.

I modified a set of washing machine motor brushes and they made the car heater motor noisy. These were ok as a temporary measure but longterm they would have worn the comutator of the motor as the carbon was too hard and eventually I would have ended up having to shell out for a new motor anyway.

If you plan to modify brushes then make sure that you use the correct grade of carbon Smile

Posted: Fri Jan 11, 2008 1:21 pm

I totally agree, this should only be done as a temporary measure. The graphite I used was very soft, pretty similar to the original brushes.I just wish it was easier to source this type of part which obviously costs a matter of pence when the main stealers would con you out of a few hundred quid to sort out something as simple as a worn brush

Posted: Mon Feb 04, 2008 6:40 pm

Great info, and great explanation of how to replace them.

Just what I needed.

EDIT: Yes, it worked Smile

Got the fan out, cleaned the brushes & commutator & stretched the springs a little. Plugged it in to test & it nearly took off !

Thanks for the info Smile

Newbie Joined: May 15, 2008 Posts: 4

Hi Si,
I gotta THANK YOU for the info (and the diagram) for the heater blower fix.

I'd just decided to put my Audi up for sale when the heater blower suddenly stopped working. The local Audi agent quoted me a probable bill of around £700 to fix it !!! Shock

In desperation I searched the net, and found this site and your message. Couldn't believe my luck Wink

Instructions followed to a T and it worked like a dream. Very Happy

I just stretched the brush springs a little and the blower is now working again.

SO I now have an Audi A4 Avant complete with working heater FOR SALE. If anyone is interested .... I'm just gonna post it on the For Sale thread.
Of course it will need aome new brushes at some point, but all is working okay for now.

Anyway, THANKS AGAIN for your great advice. Cool

Mike

Newbie Joined: Dec 02, 2007 Posts: 15

You should have stuck new brushes in when you had the motor out.

Removing the motor is the hardest part. Fitting the new brushes takes 30 seconds.

Newbie Joined: May 15, 2008 Posts: 4

Yeah I know - STOOPID EH ? Rolling Eyes

but I didn't have any brushes and I just wanted to make sure that was the problem. At least I know how to do it now.
Mike

Posted: Fri May 16, 2008 6:28 pm

Glad to be of help Wink

Si.

Posted: Tue Nov 03, 2009 1:07 pm

nearly 2 years later and heater still going strong after temp fix!

Posted: Sun Nov 21, 2010 4:39 pm

I've got exactly the same problem with my 2000 A4.

Got the glove box out no problem, but when i try to access the motor, there is 1 screw out of 5 which is not possible to get to as it's right up against the airbag and there is no space for the screwdriver to access it.

Anyone got any ideas how i can get to the motor without having to take the whole dash out?

Thanks for looking Smile

Newbie Joined: Dec 02, 2007 Posts: 15

remove or slacken the air bag bracket on the left hand side (passenger side) its held in by 4 x 10mm bolts.

With that bracket slackened off / removed then you can get a small dumpy philips head screwdriver into the top screw.

If your brushes need replaced then these are the ones you need.

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=200536884493&ssPageName=STRK:MESELX:IT

Posted: Sun Nov 21, 2010 6:37 pm

Thanks a lot, I've ordered those brushes so will try slackening off the airbag bracket and see how i get on.

Think when i finally do get into where the motor is i will be leaving this screw out when i put it back together!

Posted: Sun Nov 21, 2010 8:19 pm

OK, i've got the motor out, but i can't see where the brushes are to see if i can prolong the life of the existing ones or replace them when the new ones arrive. Can anyone help? Much appreciated!

Newbie Joined: Dec 02, 2007 Posts: 15

There's 3 small black rubber stoppers on the outside ende of the motor. Press these in with a flat bladed screwdriver and the 2 parts of the motor will pull apart.

You'll then see 2 small stainless clips. Behind each clip is a spring and a brush. Be carefull when removing the clip as the spring will ping out so catch it!