How to replace blower fan brushes.

[Ivanerrol]

W202 Blower Fan Fix

Intermittent or non operation of the HVAC blower fan in the w202 or W210 series
Is often caused by worn out fan motor brushes.
These brushes can be sourced easily on the web – particularly on U.K. ebay sites for very little monetary outlay. I sourced a set from a U.K. supplier and including post to Australia the cost was just under AU$10.00

Another fault is often the blower fan regulator. These are also easily sourced on U.K. ebay sites. Don’t bother getting a second hand module. It’s just as likely to go faulty on you in short time.

The Blower motor removal and replacement is straight foreword – unlike the previous W124 or W126 models. The fan motor is located above the front passenger kick panel.

In the case of this particular ’96 W202 C200 the blower fan would not operate at any speed using the controller switch on the console. If 12 volts was applied directly to the motor the fan did operate – but very noisily.

First step is get access to the motor.

Passenger side foot well. Under dash kick panel needs to com out.
Before getting the panel out the air inlet cover must be removed
Here’s the cover


Use a Philips head to turn the screw half a turn. Then the cover pulls out and off



The under dash panel has three Philips head screws to be removed.


The panel pulls forward and out


Next to be removed is the electrical connection from the blower fan cover

[Ivanerrol]

The blower fan cover has two clips that hold the front on tight – slide these towards the centre on both sides


Pull the cover downwards and forwards to get it off.

Get upside down in the foot well and look up you will see this
This is the blower fan motor and arrowed is the speed regulator.




All screws holding the fan motor and regulator in are Torx20 heads. You will need to buy a set of Torx bits and Torx sockets to work on W202 and W210 M.B.’s onwards.



Here’s an image of the fan motor in situ with the regulator removed. The regulator must be removed to enable you to get at all the screws holding the motor in place. Note that there are 4 screws only. The regulator is plugged into the fan motor with a largish plastic plug.



Regulator

[Ivanerrol]

Remove the fan motor


Look up into the chamber that the fan came from. Make sure there is no obstructions or dust – clean them out if there are any.



Here’s the assembled motor on the bench.



If you are simply replacing the motor with anew or second hand unit all you need to do now is put everything back in the order the items came out.

[Ivanerrol]

Repairing the motor – i.e. changing the motor brushes.

There are two screws on the top of the motor that must be removed. Also remove the regulator if it’s still on the motor. The lug for the regulator is keyed so that it can only go in one way.



After removing the two screws – as arrowed on the diagram, carefully slide the motor assembly away from the housing. You will be left with this.



See that beer bottle? It took me just one bottle to do this whole job. Removing, repairing and replacing.

Arrowed in the next image is the clip that holds one of the brushes in (there are two brushes) The clip just comes off with a screw driver – careful, there is a spring underneath.



Carefully pull the old brush out. Note the two clips and springs.




The brush must be dunsoldered from this point

[Ivanerrol]

Old techies will notice Ivanerrol’s folly in that he is using a boy to do a man’s job.

The soldering tool is tool small for the joint. When resoldering the new brush in there’s a good chance of getting a dry joint because not enough heat can be applied to the tag.

The Goldilocks choice.

One two small, one too big and the one in the middle just the right size for the job.



Remove the old brush lead, clean the tag up and it should look like this. Leave some old solder on the tag – this “tins” the tag.




Here’s the old removed brushes next to the new ones. No wonder they only work intermittently!



Solder the new brushes into place

[Ivanerrol]

Position the new brush into place




Replace the spring and holding clips



Your done.

Reassemble everything back in the order you took things apart.

Test in the car.

The fans in the W202’s are quite quiet. You should not hear much wind noise. You should hear no rattles or clunking.

Open another beer.

Started this job at 16:30 finished by 17:20

I have never done this job before.

Looked it up on the net didn’t find any images – so decided to do some.

Spare parts wreckers quoted near $200.00 for a an old fan blower motor. Chances are the brushes would have been required in a second hand unit anyway.

The stealership price was in excess of a Thousand bucks.

To do this job you must have some knowledge of how to solder plus the right tools and equipment. Buying a soldering iron and some solder down at the local electronics store plus buying the brushes and replacing them yourself is still far cheaper than buying a second hand motor at a wreckers.

[pastelgrey300D]

Outstanding thread! Thanks for posting, there is a possibility that we may end up with a 202 or 210 in the future so great to see threads like this. And proof that there is still plenty of the old DB engineering DNA in these cars, more modern cars would have one way tabs and catches or have everything pressed together instead of screws... :occasion5:

[redlaser]

I'm about to replace the blower in a W126 series 2...do u know if the procedure is the same as above?

[Tony From West Oz]

I am sure that removal would be different but the actual brush replacement would be similar. There is likely to be a different brush retainer system too.
Soldering the new brushes in should be the same.

Why not do a tutorial on the brush replacement for W126's?

Tony

[Ivanerrol]

See : http://www.benzworld.org/forums/w126-s- ... -w126.html

And of course there is always old Kent ": https://www.youtube.com/watch?v=Lwk9sGoqj4s

[redlaser]

Thanks muchly for info...I had searched for several days and did not come on the site...guess a "squeaking blower " were the key search words!

[tsharkey]

Started this job at 16:30 finished by 17:20

I have never done this job before.

Clearly I didn't have the performance enhancing drugs you were drinking as it took me 90 minutes ...

Great post and thankyou for going to the trouble, yet another item on the W202 fixed.

[Ivanerrol]

Started this job at 16:30 finished by 17:20

I have never done this job before.

Clearly I didn't have the performance enhancing drugs you were drinking as it took me 90 minutes ...

Great post and thank you for going to the trouble, yet another item on the W202 fixed.

Probably because I have all the proper tools and have been doing electronic soldering works for 45 years. :whistle:

[176bob]

Absolutely spot on, great tutorial. Thank you. Bob.

[piperjon]

Hello
I have been trying to find on the internet a set of brushes for my blower motor W202 C180 1997 Merc. But doesn't seam to be any good. Does any one know where I can pick up a pair??
I suppose ring Mercedes that maybe no loner made like a few thing you need.

As I asked if any person know where I can buy a pair. Please let me know.
All the best.
John

[Ivanerrol]

Try Ebay UK. That's where I source them.

[piperjon]

Hi guy's.
thanks Ivanerrol for showing use who have trouble with the blower fan as I did. Added the new brushes and now it works well. Thank you for all the pictures from start to finish.
Great stuff.
Cheers John