Heater fan blowing intermittently on C200 1999 ??

[fast cars]

Mercedes C200 Classic 1999 , can anyone help , the interior heater fan blows intermittently ,switching on and off whilst its set on any fan speed , in this weather its nearly impossible to drive with the glass fogging up , can anyone tell me what I should be looking at to try and sort this? The control for the fan is the simple rotary dial , no fancy climate control here


Thanks

Danny

Edited by fast cars on Sunday 3rd October 13:55

Edited by fast cars on Sunday 3rd October 13:56

[BigBen]

If its like my s-class the blower motor has a voltage regulator on it. These can and do fail with intermittent operation being a symptom. Also the blower motor bearings can fail meaning the motor can't turn at some points, can you make the blower start again by hitting a bump ?

[fast cars]

I have found sometimes hitting a hard bump on the road gets it going again ? what could I do to poss sort this ?

Thanks

[BigBen]

fast cars said:

I have found sometimes hitting a hard bump on the road gets it going again ? what could I do to poss sort this ?

Thanks

That sounds quite like the bearings on the blower motor are shagged, fix is a new blower motor.

Ben

[bolide]

fast cars said:

I have found sometimes hitting a hard bump on the road gets it going again ? what could I do to poss sort this ?

On a W124 that means the carbon brushes on the motor are worn. Your car may well be the same

Take the fan out, replace the brushes & lubricate the bearings. That'll probably sort it out. If you can't find a supplier for the brushes buy some a little bigger and file them to shape. Your local old electrical shop (assuming it still exists) will be able to help here, or you might find them on eBay

Nick Froome

[fast cars]

Cheers chaps , it is most defo the motor bearings , tried some WD40 on it and its really helped even though its not cured it , new motor or rebuild next !

[BigBen]

I might have one in stock at home, will check over the weekend if I remember

Ben