W210 / E320 ( 1996 ) Ventilation System Fan Speed

[The Sentinel]

The ventilation fan speed rotary control switch on my 1996 W210 / E320 has developed a mind of its own. It mostly runs at random fan speeds, irrespective of the rotary switch setting. I have changed the filter (which lives under the passenger side of the dashboard )

I understand that this a common problem with earlier W210 series cars. Can anyone advise how to resolve this problem? Can the rotary control switch be replaced easily ? Are these switches readily available ?

 

[Aussie Nick]

Hi. I think that your fan is similar to my 202.Take out the fan which sits above the filter.There should be 4 screws. You will also find a regulator device.Unplug all wires. Take your regulator to any auto elec shop for testing. The fan speed is regulated by this device .It works on an earthing priciple.It may be that your earth attach wire is loose and consequently as you drive along the contact changes its position. You may want to blow out the whole motor assembly with compressed air to get rid of all the built up carbon dust. Further you may want to see if you can slide out the carbon contacts(bushes) if you can on your model.It is then worthwhile to replace these. they are available . you can resolder these back into the original position. A new fan is very expensive. I was quoted $1200.00 AUS. I managed to fix the problem for $45 AUS.Some of these earlier fan assemblies come apart and you can brush out the inner core in a shallow plate of petrol. Your fan will be as good as new, And you will have avoided being done over by the stealers. Regards Aussie Nick

 

[cyps]

i just removed the filter on mine works a treat

 

[Aussie Nick]

With all due respect taking the filter out is not a cure for a fan motor which is showing signs of fatigue. If the fan motor is operating properly the filter will not present any problem to its operation. It is preferable to take the motor out for inspection and testing of the regulator rather than getting stuck without heating or air conditioning.
It is not hard to take the ventilator fan and regulator out.It will take any lay person about 2 minutes. I should have indicated that the replacement of the solder contacts (bushes) is a little more complicated and delicate. The bushes will require bedding in before they will operate the motor. If you get to this stage and get stuck email me and i will try to supply assistance.
Do not be put off by autoelcs or stealers saying that the fan motor is a throw away and needs to be replaced by a new one. This is not always the case and some of these ventilating motors are very easy and cheap to repair. The important thing to look for is that the contact bushes can be snipped off at the base of their wires , the contacts dragged gently out and the wires of the new contacts resolderd where the original ones were snipped off.

 

[jberks]

A worn fan or blocked can run slow, but not fast IMO.
Random speed is almost always the regulator. I replaced the one on my 4 year old 210 for this very reason. It would suddenly speed up on it's own, then drop to nothing, then go back to normal. It was all over the place.
Mine also whistled exactly like a worn fan bearing.
The switch is probably fine.