w210 heater fan fault

[BHS]

Hi all, I think this has been raised b4,so apologies in advance. Heater a/c fan in my 2002 e320 cdi seems to have a mind of its own. Often it will not run 1st thing on a cold/frosty morning(like now) then it will start up after 5 mins or sther times it will run ok but then stop! I have removed & cleaned pollen filter in footwell just in case it was blocked, but problem still remains. It has the normal a/c not digital climate control. All info appreciated, thanks.

 

[television]

You need to remove the motor and replace the carbon brushes. That should be the problem.

The regulator is a solid state device and either works or it does not, so other than a poor fitting spade connector it should be the brushes

 

[simon winn]

Hi,

Television I think you may be incorrect for once but my fan was always running and would never stop!. I replaced the regulator pack - pt no MA2108700210/39 - £137 = vat - easy DIY job. Simon

 

[television]

Hi,

Television I think you may be incorrect for once but my fan was always running and would never stop!. I replaced the regulator pack - pt no MA2108700210/39 - £137 = vat - easy DIY job. Simon

Hi Simon,,what I was trying to say was the regulators do not go intermittent, they either work on one speed range or not at all, they never go intermittent, they are a solid state device, and that is the way these things go.

 

[simon winn]

I should have known not to doubt you Malcolm

 

[BHS]

Thanks for that. Is motor/regulator assy in footwell or elswhere? Are any photos available for diy job? Thanks again.

 

[television]

You will have to take the motor out and check the brushes.

A late 210 should be a 210226 car


http://www.detali.ru/cat/oem_mb2.as...GA=722.626&CT=F&cat=65S&SID=83&SGR=045&SGN=01

 

[FIBAMAN]

You need to remove the motor and replace the carbon brushes. That should be the problem.

The regulator is a solid state device and either works or it does not, so other than a poor fitting spade connector it should be the brushes

I agree with Malcolm, but you need to check the condition of the commutator also. If this problem has persisted for a while the commutator can be damaged by increased sparking, which would mean a new motor. Not too difficult, but it helps if you are a slim contortionist, not a fat old b...d like me.

 

[Dosco]

You will have to take the motor out and check the brushes.

A late 210 should be a 210226 car


http://www.detali.ru/cat/oem_mb2.as...GA=722.626&CT=F&cat=65S&SID=83&SGR=045&SGN=01

Same problem:???:

Thanks for this post and answer, could not have come at a more opportune moment. Just had the motor out and the brushes whilst not worn out are very short indeed, so some 'chattering' is taking place and no doubt sticking so all I have to do is get replacement brushes.

 

[Dosco]

I agree with Malcolm, but you need to check the condition of the commutator also. If this problem has persisted for a while the commutator can be damaged by increased sparking, which would mean a new motor. Not too difficult, but it helps if you are a slim contortionist, not a fat old b...d like me.

He's right about the "fat old b...d like me" bit in my case add seized up joints

 

[television]

You can buy brushes from many places and garden machinery shops are a good source, though if they do not have the exact size you can reduce the size just by rubbing on a piece of sandpaper on a flat surface or a file,,you must take the 4 corners off,or they will stick. Another source of these bits is from a recycling center where 100's of drills etc are thrown away

 

[BHS]

Thanks all. I think I fit into f o b bracket but I will give it a go!!

 

[jberks]

I'm not sure. My experience with the regulator is that it can do pretty much anything. Mine would run slowly, then suddenly spin up to full on its own, then back down again. I guess it could go so low as to stop the fan but I will agree, the brushes are still a strong contender.

 

[television]

I'm not sure. My experience with the regulator is that it can do pretty much anything. Mine would run slowly, then suddenly spin up to full on its own, then back down again. I guess it could go so low as to stop the fan but I will agree, the brushes are still a strong contender.

For this to happen the regulator would have to be in poor contact with the heat sink, the reg starts to get hot and once over a certain temp the HFE of the device falls and will cut off once over a certain temp. Starting again from cold the cycle will repeat itself.
Once a semicondutor has in internal short / leak, there is no way back, and it cannot change. the only other way that it could fail, is if the reg had an internal leak/short, lets say very small, this will cause rapid heating of the device and it will stop / fail once over a certain temp, that is not what I class as intermitent,, sorry to go on