1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Heater Demister Blower Stopped Working!

Discussion in 'Electrics, Vacuum, Ignition and ECU' started by merc4me, Dec 6, 2012.

  1. merc4me

    merc4me Member

    Messages:
    22
    Likes Received:
    0
    Joined:
    Nov 17, 2004
    Hi guys

    1992 J Reg Merc 190e

    Haven't posted in a while but love the new look of the Forum.

    Of all the times in the year to go wrong, My Heater Demister Blower has stopped working, when I put the slider right over it used to blast air at the screen but not any more.

    Although the were occasions when it was working intermittently.

    May be a coincidence but it was working fine until I fitted a Brand New Battery, so I am thinking it could be a fuse or a loose or corroded fuse?

    Where do I find the Fuse? any other ideas would be welcome.
     
    Last edited: Dec 6, 2012
  2. television

    television Always remembered RIP

    Messages:
    164,074
    Likes Received:
    310
    Joined:
    Mar 14, 2005
    Location:
    Daventry
    Your Mercedes:
    2002 SL500, 216 CL500, all fully loaded
    First you do not say what the car is,,,, what ever it is it the chances are it will be the carbon brushes worn out
     
  3. OP
    merc4me

    merc4me Member

    Messages:
    22
    Likes Received:
    0
    Joined:
    Nov 17, 2004
    1992 Merc 190e If it is the brushes how do I replace them?
     
  4. television

    television Always remembered RIP

    Messages:
    164,074
    Likes Received:
    310
    Joined:
    Mar 14, 2005
    Location:
    Daventry
    Your Mercedes:
    2002 SL500, 216 CL500, all fully loaded
    You will need to get the motor out, its top left 32. I may have the instructions, but I cannot check right now as I will be off air for a while reloading Windows 7 pro
     
  5. brianbrian

    brianbrian Senior Member

    Messages:
    2,747
    Likes Received:
    181
    Joined:
    Sep 27, 2008
    Location:
    cockney in the West Country
    Your Mercedes:
    w124 250D, SL129-deisel
    Have you made sure the water channels under the blower are not blocked, as they do tend to get a lot of water this time of the year. Hope this helps
     
  6. OP
    merc4me

    merc4me Member

    Messages:
    22
    Likes Received:
    0
    Joined:
    Nov 17, 2004
    Hi brianbrian

    No I never checked that, I will have a look
     
  7. television

    television Always remembered RIP

    Messages:
    164,074
    Likes Received:
    310
    Joined:
    Mar 14, 2005
    Location:
    Daventry
    Your Mercedes:
    2002 SL500, 216 CL500, all fully loaded
    I am still off line and cannot give you the info yet, sorry
     
  8. OP
    merc4me

    merc4me Member

    Messages:
    22
    Likes Received:
    0
    Joined:
    Nov 17, 2004
    I think I've found the problem but what is the solution?

    When I put the demister on full (92J 190e) It runs for a couple of seconds, then cuts out.

    Looking under the bonnet I can see the fuse has blown on the fan and when I have replaced the fuse and switched it on it blows the fuse again!

    Probably something to do with all the Wet Weather but I cannot see any water trapped anywhere.

    I would have though the heat under the bonnet would have dried it out but it seems not.

    Anyone else had this problem and managed to fix it?

    Also: Just behind the battery are a couple of wired coils, surrounded by a sort of protected metal heat guard.

    When you try and turn on the fan, they heat up and glow bright red like a mini electric fire! is that supposed to happen?

    Any ideas?
     
  9. Some guy on the internet

    Some guy on the internet Senior Member

    Messages:
    1,350
    Likes Received:
    9
    Joined:
    Jan 21, 2010
    Your Mercedes:
    A few.
  10. huey

    huey Senior Member

    Messages:
    818
    Likes Received:
    3
    Joined:
    Feb 13, 2011
    Location:
    Nottinghamshire
    Your Mercedes:
    W203 cdi 2004 Estate
    The wire coils you refer to with the "metal box" is the heater blower resister, it regulates the fan speed, if this is glowing red that means it is getting very hot and should not be doing so. I would hazard a guess that your actual blower itself is getting stuck maybe due to some debris stuck in there or could even need lubricating if not spinning freely, it would be stuck and the resister is glowing red (overheating) trying to get it spinning. Hence blowing the fuse
     
    Last edited: Dec 9, 2012
  11. OP
    merc4me

    merc4me Member

    Messages:
    22
    Likes Received:
    0
    Joined:
    Nov 17, 2004
    Hi Yes

    That was what I was thinking, but how to you get to the fan to give it a spin to free it off?
     
  12. huey

    huey Senior Member

    Messages:
    818
    Likes Received:
    3
    Joined:
    Feb 13, 2011
    Location:
    Nottinghamshire
    Your Mercedes:
    W203 cdi 2004 Estate
    If your car does not have aircon, you should be able to get to the blower by removing the front scuttle and the wiper mechanism.
     
  13. Some guy on the internet

    Some guy on the internet Senior Member

    Messages:
    1,350
    Likes Received:
    9
    Joined:
    Jan 21, 2010
    Your Mercedes:
    A few.
    Read post 9 & follow the link.
     
  14. OP
    merc4me

    merc4me Member

    Messages:
    22
    Likes Received:
    0
    Joined:
    Nov 17, 2004
    I Think I know what happened, as this time of the year the car gets covered in leaves from a nearby tree and I'm always having to clear them away from under the wiper.

    When these leaves are very dry they fragment into small pieces and I reckon that a bit of debris is stopping the fan from spinning.

    If I just remove the cover plate under the Wiper, would that give me enough room, to get my hand in and give the fan a spin to free it off (while the fan is switched off)

    Or would I need to unbolt the Wiper as well?

    As if I would have to do that, I would wait better weather before pulling it all to bits.
     
  15. Some guy on the internet

    Some guy on the internet Senior Member

    Messages:
    1,350
    Likes Received:
    9
    Joined:
    Jan 21, 2010
    Your Mercedes:
    A few.
    Extremely unlikely. The holes in the wiper grating are very small. The blower motor is in the vertical position with good clearance around & underneath it where there is a good sized drain hole.
     
  16. OP
    merc4me

    merc4me Member

    Messages:
    22
    Likes Received:
    0
    Joined:
    Nov 17, 2004
    Just before the fuse blows, the fan spins for a few seconds.

    It may just need turning over by hand or a drop of oil, so would I need to take the wiper motor off?

    Or would there be enough room to get my hand in to turn the fan by hand?
     
  17. television

    television Always remembered RIP

    Messages:
    164,074
    Likes Received:
    310
    Joined:
    Mar 14, 2005
    Location:
    Daventry
    Your Mercedes:
    2002 SL500, 216 CL500, all fully loaded
    I may have a secondhand good one that you can have for the cost of the postage
     
  18. television

    television Always remembered RIP

    Messages:
    164,074
    Likes Received:
    310
    Joined:
    Mar 14, 2005
    Location:
    Daventry
    Your Mercedes:
    2002 SL500, 216 CL500, all fully loaded
    What size is the fuse for the fan 15 amp
     
  19. Frontstep

    Frontstep Senior Member

    Messages:
    7,406
    Likes Received:
    1,298
    Joined:
    Apr 22, 2007
    Your Mercedes:
    T210 320cdi
    With its history of intermittent working it sounds like you will have to get it out.
    Brushes are a favourite.
    Follow the link !!
     
  20. OP
    merc4me

    merc4me Member

    Messages:
    22
    Likes Received:
    0
    Joined:
    Nov 17, 2004
    Hi Yes 15 amp fuse

    If not leaves then it may be a build up of gunge, not a great time of the year for having to pull the car to bits.

    I just want to get it working and will do a proper job on it in the spring.

    I just wish there was an easy way that I could spin the fan by hand without taking the wiper and motor off.

    Does anyone know how long it takes to get to the fan?
     

Share This Page