Heater problems E240

[debcr]

Had an intermitant problem with heater for over a year - typically it stops working for a week - then is ok for a few more months. This time stopped working for a few weeks (blower not blowing out anything) so I have took car to an indy (not merc specialist) - He has diagnosed the regulator as being faulty - I got a new one from mercedes and he fitted it but still dosn't work.
The fan itself is ok - as he got it going manually - he needs the car in for a another look when he can spend more time on it.
My question really is ---- are the heaters and workings on mercedes much the same as any other car- i don't want him stripping down the dash when it may not be necessary or have him changing bits till he gets the right fix. Incidently i do trust him i,m just pd off that i am £136 down and its still not working. Also any ideas what might be the problem now. He has refitted the old regulator in case the new one is damaged.
Thanks

 

[Stevie A]

Could be a blown or loose fuse or loose or dirty electrical connection going to blower / regulator.

 

[luders79]

Hello,
What heater controls have you got? Manual dials Or digital display.
I would suggets check the voltage getting down to the regulator. If i remember right the regulator has three wires one of which is a control wire that comes down from heater controls. The voltage down this wire should change when you change the fan speed. Post what colour wires are and it might jog my memory of what colour control wire is.

Hope this is of some help

Luders

 

[debcr]

They are manual dials, I am unable to check as i am disabled but thanks anyway. I just thought it strange that an intermittant fault could be the result of two componants failing. Hopfully I will just be billed for the correct parts/labour.

 

[mickbilly]

heater fan

hi,

I had this same trouble for a long time, tried everything like you.

did not think it was the blower as I could give it a turn manually and it worked.

it is a faulty blower motor, believe me.

there is a pollen filter next to blower which needs changing regularly( non MB services tend to miss changing this)

the filter blocks up with the result that the fan has to be run constantly on high speed which in turn soon burns the bushes out hence faulty intermittent blower.

I did everything, fitted bushes, new regulator, second hand blower ( which must of had same fault) fitted new blower 6 months since no trouble since.

dronsfield mercedes, of Oldham, will send one mail order for about £ 100. i'm not connected to them honestly.

I know of one MB main dealer who fits at least 3 new blowers a week.

don't forget the new filter!!

hope this helps

 

[debcr]

If you juice up the motor direct from a power scource and it works how can it possibly be the motor thats faulty. or am i missing something.
thanks

 

[mickbilly]

believe me I did all you did and more, the spindle the motor turns on will be damaged by the worn bushes. this spindle ( commutator ) is split into segments which causes an alternating charge to the coil which in turn creates a magnetic field round the spindle. this causes the steel on the spindle to pull towards the magnet. if some segments are damaged and fused together and the bushes stop on this damage all the power in the world will not start it when switched on again, unless! the fan is moved, manually or disturbed whilst removing the fan, off the damage. once it starts the momentum skips it over the damage and it keeps going.
phew!!
probably someone who knows what they are talking about will say thats a load of s***t but thats the only way I can explain it with my limited knowledge. I just know what happened to me.
put this to your mechanic.
If you are getting power to the regulator and then to the blower why does it not work?

 

[Wezzel]

Make sure it's not the rotary switch. Take out the switch assembly. Give the switch component a good soaking with contact cleaner and keep spinning it back and forth for a few minutes.

Worked with mine.

 

[debcr]

The garage changed the controller and after one day it is still working. I still do not know why the regulator was changed first as it should have been obvious that the controller was faulty, and he was unable to find the old regulator when it was asked for.
Anyhow, assuming he did get it right and diagnosed the faulty regulator and controller and replaced both, what would you expect to pay for labour alone (pre vat) and how much time should this job take a competant mechanic.
Many thanks to all