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Merc C Class Heater Fan

Posted: Thu Feb 11, 2010 3:48 pm
by Simon Site Manager
Hi Guys,

The fan on my car is in trouble, I know the brushes need replacing but the comutator seems to get burnt and then stops running. The comutator seems damaged and scars the brushes which causes sparks and then leaves deposits on the comutator.

My question is, can a comutator be renevated?

Thanks,
Simon

Posted: Thu Feb 11, 2010 5:59 pm
by Hitch
Bar from cleaning the segments, theres probably not enough meat to be able to machine them true....dont know really.

Big ones can be refurbished for sure.

Posted: Thu Feb 11, 2010 6:52 pm
by ultimatehandyman
Might be as well pricing up a new fan.

I have used these quite a bit in the past-

http://www.eurocarparts.com/ecp/p/Car-Parts

Posted: Thu Feb 11, 2010 9:32 pm
by ajstone
You can get a soft abrasive stick that you use where the brushes make contact.
I'd try that first.

Posted: Thu Feb 11, 2010 9:45 pm
by Simon Site Manager
Thanks for the help guys, the comutator is quite pitted round the bottom, I have cleaned it up with wet and dry poked thro' where the brush goes, it works fine for say 5 mins then the brushes start to spark and the comutator gets black deposits on it (not carbon, as they are meant to be copper brushes but seem more like graphite-very soft).

A new motor is 200 quid or so, so am looking at a breaker, but according to merc forums this is an inherant problem so I'm guessing the fan will be the first thing to go.

Cheers anyway!
S

Posted: Mon Mar 08, 2010 12:58 pm
by Raf
also try GSF (german swedish french)

needs a new motor mate unfortunately.

Posted: Mon Mar 08, 2010 1:44 pm
by EJJ150847
Sometimes what can happen is the commutator will wear and the insulation between the commutator segments becomes proud of the segments.

Then what is needed is to 'undercut' the insulation to below the segments.
This is easy on large motors, on smaller motors it is fiddly, you have to dismantle the motor put the armature in a holder and using a hacksaw blade, ground to the size of the insulator, 'undercut' the insulation.

On large motors we used to put them in a lathe and use the toolpost, but I'm talking BIG motors.

I don't think you will rescue the motor, look around at Breakers yards.



John

Re: Merc C Class Heater Fan

Posted: Tue May 11, 2010 4:09 pm
by funnyceline
A soft abrasive stick could be a great thing to use if that is the case. It could be soft enough not to override the surface.