Heat/AC blower fan working on/off
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Joined: Oct 2014
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2006 Mercedes Benz S430 4Matic
Heat/AC blower fan working on/off
The heater blower motor I guess, or something, is acting up. For about 6 months now it has sometimes not worked at all, meaning that when the heat or AC is on, there is nothing happening, all looks like it's working but it's all quiet and the fan does not come on. This may last for a couple drives or less or a bit more, then all of a sudden it works perfectly again for days at a time, sometimes weeks, and then again won't come on. I thought maybe it was the cold because since it got warm it hasn't happened but now it happened twice in the last week, again only for the two days, and working the rest of the time.
Before I go and buy the Heater Blower Motor w/Fan Cage (with or without transistor/regulator or whatever it a buddy mechanic of mine told me) I wanted to ask here if anyone has had this problem and if so what it may be. I just don't understand it working on and off, usually a mechanical thing like this either works or it doesn't, especially fans etc., and it's usually the switch or some electrical or electronic control that is at fault, but I could be wrong.
Any advice would be appreciated, thank you!
Before I go and buy the Heater Blower Motor w/Fan Cage (with or without transistor/regulator or whatever it a buddy mechanic of mine told me) I wanted to ask here if anyone has had this problem and if so what it may be. I just don't understand it working on and off, usually a mechanical thing like this either works or it doesn't, especially fans etc., and it's usually the switch or some electrical or electronic control that is at fault, but I could be wrong.
Any advice would be appreciated, thank you!
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From: Ball Ground, GA (N of Atlanta)
2003 S500 2007 GL450
Poor electrical connection would be my first guess, worn or sticky motor brushes would be my second guess.
It isn't too difficult to get to the blower motor. The regulator is mounted in the center of the blower assembly. There is a heavy power wire from the car system plugged onto the regulator, and a heavy wire from the regulator plugged onto the blower motor. It would be pretty simple to check for power on these two wires while the blower isn't working. That would tell you whether there is power or not from the car to the regulator, and from the regulator to the blower.
This would tell you where to start looking for the problem.
It isn't too difficult to get to the blower motor. The regulator is mounted in the center of the blower assembly. There is a heavy power wire from the car system plugged onto the regulator, and a heavy wire from the regulator plugged onto the blower motor. It would be pretty simple to check for power on these two wires while the blower isn't working. That would tell you whether there is power or not from the car to the regulator, and from the regulator to the blower.
This would tell you where to start looking for the problem.
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2006 Mercedes Benz S430 4Matic
Thank you for the information, it is what I figured. But I do have a follow up..
If it is electrical, where would I look for that? Do you mean the simple connector to the motor where the motor itself is, check that and see if it is loose or maybe corroded or something similar? Or is it a connector that controls all kinds of things and is hard to get to?
And secondly, if it is worn or sticky brushes, that would require a new motor blower right? Here is what I found, is that what I'm looking at in the case of the brushes?
http://www.ebay.com/itm/Blower-Motor...QAAOSwAANY63uP
The one above is a low price, there are others that are three times that so I'm a bit confused about the matter, and like I said my mechanic said something about it coming with a transistor (or regulator) or not, and with it is much more expensive, I have no idea. But please check the above and let me know if that's it if indeed it ends up being the brushes (how would I check for that, just take it out and see if it spins normally with a finger? check for dust?)
Thank you again in advance.
If it is electrical, where would I look for that? Do you mean the simple connector to the motor where the motor itself is, check that and see if it is loose or maybe corroded or something similar? Or is it a connector that controls all kinds of things and is hard to get to?
And secondly, if it is worn or sticky brushes, that would require a new motor blower right? Here is what I found, is that what I'm looking at in the case of the brushes?
http://www.ebay.com/itm/Blower-Motor...QAAOSwAANY63uP
The one above is a low price, there are others that are three times that so I'm a bit confused about the matter, and like I said my mechanic said something about it coming with a transistor (or regulator) or not, and with it is much more expensive, I have no idea. But please check the above and let me know if that's it if indeed it ends up being the brushes (how would I check for that, just take it out and see if it spins normally with a finger? check for dust?)
Thank you again in advance.
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From: Snowville, ID
W212 E350; W166 GLC300; W164 ML550; W164 ML63; W221 S65; W220 S430; Escalade ESV
It works intermittently so I would spray the wire harness and the motor brushes with WD40 first to see if anything changes. You might not have bad parts but poor connections.
MBWorld Fanatic!
Joined: Dec 2012
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From: Ball Ground, GA (N of Atlanta)
2003 S500 2007 GL450
To each his own, but I have a very low opinion of WD-40 as an electrical cleaner.
CAIG DeoxIT D5 is one of the best contact cleaners available.
If you can catch the blower not working, checking for power on the two heavy connections will tell you whether the problem is in the car power system, in the regulator, or in the blower motor. You can then proceed to check the problem area.
CAIG DeoxIT D5 is one of the best contact cleaners available.
If you can catch the blower not working, checking for power on the two heavy connections will tell you whether the problem is in the car power system, in the regulator, or in the blower motor. You can then proceed to check the problem area.
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2006 Mercedes Benz S430 4Matic
Ok guys I will do that, but could you point me to the actual part that I need if indeed it is the part? I find that when I type AC Heater Blower for my car the prices range from $69 to $399 and I have no clue, so before my significant other who loves to spend big money buys the most expensive part could you give me a link or two?
Here is what I found so far, is this what I'm looking for?
This one is expensive: http://www.ebay.com/itm/Replacement-...wAAOSwopRYdjlo
This one is cheap and looks the same and appears to be the real deal and good company:
http://www.ebay.com/itm/Blower-Motor...QAAOSwAANY63uP
Rest assured, I will WD40 (or the other) ta heck out of that blower and clean the connectors but just in case..
Thank you, respectfully.
Here is what I found so far, is this what I'm looking for?
This one is expensive: http://www.ebay.com/itm/Replacement-...wAAOSwopRYdjlo
This one is cheap and looks the same and appears to be the real deal and good company:
http://www.ebay.com/itm/Blower-Motor...QAAOSwAANY63uP
Rest assured, I will WD40 (or the other) ta heck out of that blower and clean the connectors but just in case..
Thank you, respectfully.
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Newbie
Joined: Apr 2017
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2005 S 500
I had virtually the same problem a couple years ago. They replaced the blower motor and various other things, but the problem persisted. FINALLY they found this rather largish fuse, about 1" diameter and about 3" long. It was burned looking. They replaced that, and no more problems.
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Newbie
Joined: Jun 2016
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2004 S500
I have not fixed mine yet as the blower fan is intermittent as well (2004 S500). I have found when it stops working I can located the fuse under the hood in the box on the passenger side, apply pressure and wiggle it a little and the fan comes back for a while. For some reason the fuse is sitting in a tall fuse holder. There must be a poor connection in this holder. One day I will take time to figure it out and fix it. I only found the issue after the problem initially occurred and I pulled the fuse to check it. It was fine and when I put it back in the fan started working.
Super Member
Joined: Dec 2007
Posts: 980
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2005 S500 Designo
I had virtually the same problem a couple years ago. They replaced the blower motor and various other things, but the problem persisted. FINALLY they found this rather largish fuse, about 1" diameter and about 3" long. It was burned looking. They replaced that, and no more problems.
MBWorld Fanatic!
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From: Ball Ground, GA (N of Atlanta)
2003 S500 2007 GL450
TomMB made two posts in 2017, hasn't been heard from again.
Before you get too involved in hunting for a bad fuse, you might try plugging the power wire that feeds the regulator directly onto the blower motor. If the blower then runs at full speed, you have a bad regulator - which isn't unusual.
Before you get too involved in hunting for a bad fuse, you might try plugging the power wire that feeds the regulator directly onto the blower motor. If the blower then runs at full speed, you have a bad regulator - which isn't unusual.
