reostat?

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Anyone know what the reo-stat or rheostat is responsible for in the heater box alongside the blower fan?
And how come it costs more to replace than the blower fan itself - quoted £223.63p retail.

Thanks,
Keith.

 

[Bolide]

Rheostat

Is there a rheostat or a resistor pack? I thought there was a resistor pack somewhere that gives the different fan speeds by dropping voltages across resistors

If it is just a simple resistor pack I'd repair it - or get my local TV repair shop to repair it - rather than pay £223. The resistors you'd need might cost all of £1 each


Nick Froome
www.w124.co.uk

 

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Thanks for the tip Nick, but where is the heater box situated and how easy is it to get to it?

Keith.

 

[Bolide]

Heater box

The fan is in the engine compartment under the jump wiper. It's engine-side of the firewall. The heater itself is in the car buried under the dash

There's just one connection (2 wires) to the fan motor so the speed control must be in the cabin. I read somewhere that on a 190 it's on the passenger side of the centre console so it's probably the same on a W124

You'll need to locate the PDFs with the wiring circuit and the part locations for your car. That'll make life easier

If the fault is that the fan doesn't run at all then it's likely the motor. Ditto if the fan is intermittent. As the motor bearingss & brushes wear the brushes make bad contact. Sometimes a sharp slap on the dashtop will get them working!

If the fault is that it doesn't run at some speed settings then suspect the resistor pack or switch

I assume this is in a W124


Nick Froome
www.w124.co.uk

 

[Bumper]

Anyone know what the reo-stat or rheostat is responsible for in the heater box alongside the blower fan?
And how come it costs more to replace than the blower fan itself - quoted £223.63p retail.

Thanks,
Keith.

What car is it for? if its for the w210 it is under the dash at the passengers footwell, it is in the same housing as the fan motor.

Have a look here http://forums.mercedesclub.org.uk/showthread.php?t=12258&highlight=fan+resistor

 

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Yes Nick, your bang on - as always.

It is the E280, Motor fan will not come on for 2-3 miles or so & when it does all works fine in any speed untill I stop & switch ign off again.

Just before having this problem, I detected a low whine coming from motor, and stays there on low speed regardless of trying to clear it by switching to higher in an effort to clear it!

So I guess its the blower brushes/bearings gone up the pictures.

Its probably due to car running up nearly 200k.

Thanks for your good advice Nick.

BTW = If you had the same problem with one of your E classes in B'ton where you live, who would you take it to, or would you tackle the job yourself?

Keith.

 

[Bolide]

Fan problem

My fan's doing the same thing. It's a real pain getting the thing out so I lubricated mine & left it - and of course it went intermittent again two days later

The plain sleeve bearings on the motors tend to wear and the shaft starts moving around & becoming noisy. Also the commutator & brushes wear. Traditionally you just polished the commutator, cut back the insulators between segments and replaced the brushes and the motor worked fine - or it did on my Scalextric when I was a kid. But if the bearings are worn it's probably time for a new motor

I've replaced fans in other cars but it's always a problem getting one to fit exactly as there are lots of versions that differ just slightly and there are single & dual fans. I will call Car Electrics in Brighton and see if they can fix the motors and I'll also see if there's a local motor repair shop

If not it's down to Mercman!


Nick Froome
www.w124.co.uk

 

[andy_k]

taking a W124 dashboard apart looks a bit like this series of pics

http://photos.wanadoo.co.uk/album/1259925

nothing to do with me so big thanks to the guy who provided the photos

Andy

 

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Thanks to all for your input, & to andy-k for those pics.