Blower Fan Stuck On Full

[craigdm]

Hi,

I was driving to work this morning (2000 CLK 3.2) when all of a sudden the fan started blowing at full speed. I tried changing the fan speed dial, and even turning off the A/C, but nothing would stop the fan.

Whan I got to work, and turned off the ignition, the fan still kept going at full speed even when I actually removed the key. Since I don't want to return to a flat battery, I found the right fuse under the bonnet and removed it. This (surprise, surprise) stopped the fan.

I've had a quick search of the forum, but could only find a reference to a case where the fan was on at position 2 with the key. There didn't seem to be a final conclusion to this thread.

Any help would be very gratefully recieved.

Thanks.

 

[craigdm]

Sad though it maybe to reply to your own thread..here goes.

Further searching of the fora have thrown up the possibility that it maybe a faulty 'Electronic Blower Regulator' unless that is there's a duff relay somewhere in the circuit.

Can anyone help me with this problem, could it be something else ??

If it is the regulator, can anyone direct me to where the best place to buy the part from is, how much it might cost and if it is an easy job to change (pictures would be nice, as I've no idea what it looks like or where it is !!!).

I'm not being tight here, it's just that my nearest indep garage is about 15 miles away, and with my wife being away this week, getting the car there is a bit of a problem.

 

[BlackC55]

It is attached to the motor.(passenger footwell) It is silver in colour and has fins to cool it. A breakers would be your best bet. Have a look at www.partsgateway.co.uk.

 

[craigdm]

It is attached to the motor.(passenger footwell) It is silver in colour and has fins to cool it. A breakers would be your best bet. Have a look at www.partsgateway.co.uk.

Many thanks for the reply... When you say attached to the motor, I assume you mean the fan motor ??...Is it easy to get to, or does it involve removing lots of interior trim ?? Basically, could I do this job myself ??, and do I need a specific part number, or are they all the same ??

Thanks for your help, getting a bit worried at the mo, as I'm due to use the car next week for a little golf break...

 

[jberks]

Remove the passenger under dash tray and look up behind. You should see the bottom of the fan housing. You will also see a rectangular plug with 3 wires running into it. That plug goes directly into the regulator. pull the plug down. You will then have to remove the 10 or so posi screws that hold the bottom cover on and remove the cover. The regulator is then obvious. remove 2 screws and drop the unit, removing the 2 spade connectors (going to the fan).
pop in a new one and and Bobs your relative. 25 mins if you take your time.

Personally, as these units are known to be trouble, I'd bite the bullet and get a new one - around £120 from memory.

 

[craigdm]

Before I fork out the cash...is there anything else that might be causing the fault ???

Or is this component a safe bet ??

Car had a 12 months warantee when I bought it, but the guy is proving hard to track down...He never answers his phone !!!. Very surprising really, as I still owe him a balance of £200 for the car (he told me to keep it, while he 'tracked down the service history'..never heard anything else from him, and that was 5 months ago!!!).

Do you think this component would be covered on the warantee, and so make it worthwile trying to contact him ?? It's not a main dealer, so I suppose the warantee won't be the best !!!

 

[jberks]

On the warranty your guess is as good as mine. Odd that he didn't get in touch, I suspect the history wasn't as he claimed or he just couldn't be bothered. Either way, the £200 you've saved could be used against the cost of the part.
As far as the fault is concerned, I can't think of anything else it could be.
However, you could test the plug quite easily. 3 wires, constant live, variable switched live and the -ve earth. From memory the centre wire is the switch wire and the voltage on this should vary according to the switch setting. So get a multi meter and test the centre pin. With the switch on 0, you should see 0v and on max it should be, say, 7v. If this is the case, then the switch is performing correctly and the regulator has an internal short.

 

[craigdm]

Thanks again for your help...

I think I'll just fork out the cash and have a bash at fitting it myself..
Are there any diagrams available showing this area ??
With my old MG ZT I had a great CD Rom that showed the whole breakdown of parts...I'm a automotive design engineer, so should be able to understand any drawing available

I'll report back, and hopefully close this thread soon !!

 

[television]

They are on Ebay from time to time, around £45 I think from the dealer, it can be test on a meter and from memory one lead goes open circuit

 

[craigdm]

Had a quick look at the footwell when I got home, and it looks like quite a nice tight installation.... Any tips of removing the trim panels ??

Any on-line diagrams would be nice too....

Thanks once more...in advance.

 

[television]

http://www.detali.ru/cat/oem_mb2.as...GA=722.607&CT=F&cat=45Y&SID=83&SGR=045&SGN=01

395 is the regulator

 

[jberks]

The under dash tray is easier than it looks - a couple of screws and it comes down.

 

[craigdm]

The under dash tray is easier than it looks - a couple of screws and it comes down.

Like I said, I only took a quick look. I did see a couple of screws on the side of the centre consule, but I didn't think these were attached to the trim (look more like fasteners for the vent).

Wife's gone away on business, so I've got her car for a couple of days. Thought I might have a bash at removing the regulator when I get home later (then there's plenty of time for me to take it to a garage when I mess it up )

 

[craigdm]

Sorry to drag this one up again, but out of interest I used the link provided earlier in the thread in order to see if there was a used part available, and to find out just what the difference in price was...

However, the breakers need a part number in order to search their database...Could one of you very kind members help me with this ??

Not sure if there are lots of different ones fitted, but my chasis number is WDB2083652F120886 if this is any help...

 

[jberks]

why not kill 2 birds with one stone. Ring the dealer, quote your chassis number and ask for a price and part number. Then you'll have the correct part no (they can vary) and you know exactly how much you'll be saving.
Its always worth asking as MB revise their prices from time to time. I recently bought a cup holder off ebay. Curiosity got the better of me and I rang the dealer. For all the hassle of bidding, getting something that looks a tad used etc I think I saved a fiver!

 

[craigdm]

Okay, here goes....

Taking the good advice given above, I rang the main dealer and got the part number. Managed to order a used part from the link given in this thread. £41 compared with £150 new. Part hasn't arrived yet, but thought I should have a look at the job, so striped down the trim in the footwell to find ...... a swimming POOL !!!

With the help of this great forum, I managed to find the drain hole, and cleaned it out. Didn't actually feel that blocked. Just a couple of questions..
1. I couldn't find a corresponding hole on the drivers side, does one exist ??
2. The flap on the nearside just feeds out into the engine bay, is that correct ?? I saw the big raceway section hole leading to the wheelarch, is that the limit of the drainage system?

Anyone got any good advice regards to drying out the car ??.. I've removed the mats and trim, and got them drying out in the house, but it's still wet in the back, and under the seat where I can't reach.

Now to the main job of replacing the regulator. I think I've found the component, but it looks like I may need to remove the whole fan blower to remove it. Is this right ?? The fan looks like it's held in by 3 or 4 'star' screws...guess who doesn't have the right bit

Many thanks for sticking with me on this one. Any help or advice would be gratefully recieved.

 

[television]

Drying the car is the hardest bit, can you get the rear seat out, if you could you could hire a small de humidifier that would suck up the moist air, things like heat lamp or fan heater work well but great care is needed to avoid damage to the upholstery.
A set of torx bits do not cost much, and yes the regulator is normally attached to the fan, so you do have to remove it.

If you want to know how to remove the seat, please ask

 

[jberks]

Drying is difficult - the key I always find, especially this time of year is air flow. Ideally find somewhere secure and leave as many things open as you can. I once had a rover cabrio dried out by having it parked in a bodyshop oven overnight - depends if you can find one willing but they may do it for a small charge.
As regards the regulator - I believe it is the same setup as my 210 saloon. That was removed in-situ. From memory it was held to the housing by 2 screws that were easily accessible from underneath. Once you get th enew one in your hand it may be clearer.

 

[craigdm]

Thank you very much gents for your help on this.

I've now replaced the regultor and everything seems to be working fine. All in all a very easy job, and if I can do it, then anyone should be able to. HAd to buy a set of star bits though !!! (£7.99)

Just one more question... the part I recieved from the breakers was not very well packaged, and as a result 2 of the 'nodules' on the back face had broken off. I can't decide if these 'nodules' are for cooling or part of the resistor circuits. Cooling was my first guess, but then I noticed that they are all different lengths. Can anyone shed any light on their purpose, and as to if the two broken ones may mean the part won't work properly.

Thanks once again.

 

[television]

Thank you very much gents for your help on this.

I've now replaced the regultor and everything seems to be working fine. All in all a very easy job, and if I can do it, then anyone should be able to. HAd to buy a set of star bits though !!! (£7.99)

Just one more question... the part I recieved from the breakers was not very well packaged, and as a result 2 of the 'nodules' on the back face had broken off. I can't decide if these 'nodules' are for cooling or part of the resistor circuits. Cooling was my first guess, but then I noticed that they are all different lengths. Can anyone shed any light on their purpose, and as to if the two broken ones may mean the part won't work properly.

Thanks once again.

If you mean the alli fins, that is all part of the heat sink where the heat is dissipated to the outer edges, it is finned to increase the surface area.

The electronic part is encapsulated