Help: Can't get AC fans to turn off. Even when car is off? - Mercedes-Benz Forum

Reply
 
LinkBack Thread Tools Display Modes
post #1 of 12 (permalink) Old 09-04-2010, 10:55 AM Thread Starter
BenzWorld Junior Member
 
Date registered: Apr 2008
Vehicle: 97 E320
Location: Mobile, Al
Posts: 24
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Send a message via AIM to stewmeistr
(Thread Starter)
Help: Can't get AC fans to turn off. Even when car is off?

97' E320.

About a month ago, the backlight in the climate controller goes out. Just a minor pita. Well, two days ago, the wife came home and says the fans won't turn off? Interesting....

So, I go check it out and sure enough, the climate controller won't increase or decrease the speed of the fans. The only thing it seems to do is temperature and compressor on or off. Well, I'm thinking the controller gave up the ghost and a new one is in order. Found one, installed it and it backlights now, but nothing else changes just like the last controller?

So, the problem:
The fans stay on, even when the key is out of the car?? I can't find a fuse to disable them and its killing my battery. So I disconnected the battery to prevent a further problem with it and here I am looking for help before the dealership gets the nod.

Can anyone shed some light on this problem for me?
Thank you in advance,
Rob
stewmeistr is offline  
Sponsored Links
Advertisement
 
post #2 of 12 (permalink) Old 09-06-2010, 03:12 AM
Outstanding Contributor
 
keyhole's Avatar
 
Date registered: Sep 2006
Vehicle: 2004 CLK 240 Coupe
Location: Norfolk. UK
Posts: 10,462
Mentioned: 10 Post(s)
Quoted: 356 Post(s)
Just for clarification here... you refer to the fan staying on with the ignition key out.

Are you referring to the auxilliary fan (M4) located by the radiator?
or the A/C blower (A32m1) located below the glove compartment?
keyhole is online now  
post #3 of 12 (permalink) Old 09-06-2010, 04:42 AM
BenzWorld Elite
 
Diesel Benz's Avatar
 
Date registered: Dec 2005
Vehicle: 222.132 & 221.122 & 212.025 & 906.633
Location: Europe
Posts: 10,322
Mentioned: 3 Post(s)
Quoted: 34 Post(s)
Quote:
Originally Posted by keyhole View Post
Just for clarification here... you refer to the fan staying on with the ignition key out.

Are you referring to the auxilliary fan (M4) located by the radiator?
or the A/C blower (A32m1) located below the glove compartment?
I assume he refers to the A32m1 in which case it would be the blower regulator most likely but I was about to ask the same question as you did, it was not absolutely clear from the message.
Diesel Benz is offline  
post #4 of 12 (permalink) Old 09-06-2010, 04:20 PM Thread Starter
BenzWorld Junior Member
 
Date registered: Apr 2008
Vehicle: 97 E320
Location: Mobile, Al
Posts: 24
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Send a message via AIM to stewmeistr
(Thread Starter)
Sorry for the confusion. Not the radiator fans. It doesn't even sound to me as if it were the blower fan under the passenger compartment, but almost like a fan of some kind under the dashboard in the center of the hood? I don't know how else to explain it. My wife has looked through the manuals and thinks that its almost as if the car is stuck in "economy mode" if that makes any sense?

I can tell you that it makes no difference to have the push button controller exchanged. There is a fan on regardless of the car being on or key in the ignition and it pushes air out of the vents.

Thank you for the help.

A final note, I did put in a "better blower relay" (forgotten what fix that was called) back a couple of years ago. That has worked fine for years.

Rob
stewmeistr is offline  
post #5 of 12 (permalink) Old 09-06-2010, 05:35 PM
Outstanding Contributor
 
keyhole's Avatar
 
Date registered: Sep 2006
Vehicle: 2004 CLK 240 Coupe
Location: Norfolk. UK
Posts: 10,462
Mentioned: 10 Post(s)
Quoted: 356 Post(s)
stew

I do not fully understand this fault, which is independant of the ignition switch. DBs suggestion above that your electronic blower regulator (N29) could be faulty makes sense. It is installed very close to the blower unit under the glove box. Getting to it involves removing the panel underneath, and probably the glove box itself.

I took a look at your fuse boxes, and reckon that this fuse should isolate the blower motor.

f7 (15A)
fuse block A
Fuse & Relay box F1, located in the engine bay.

However, we have heard of corrosion in Fuse and Relay box F1 (from rainwater ingress) causing this type of fault, so take a good look at your fuseboxes now.
keyhole is online now  
post #6 of 12 (permalink) Old 09-06-2010, 07:48 PM
BenzWorld Elite
 
2000 C280 Sport's Avatar
 
Date registered: May 2008
Vehicle: Mercedes-Benz
Location: New York & Florida.
Posts: 1,624
Mentioned: 0 Post(s)
Quoted: 22 Post(s)
You need to PM a guy on here named OHLORD as soon as possible. He is a W210 Master.

2015 Dodge Caravan (9K) NY
2012 Mercedes E350 4Matic Sport (40K) NY
2006 Mercedes CL600 (48K) NY
2005 Mercedes CLK55 AMG Coupe (28K) FL
2005 Mercedes C240 4Matic (200K) NY
2004 Mercedes CLK320 Cabriolet (45K) FL
2002 Porsche 911 C4 Coupe (69K) NY
1999 Ferrari F355 6 Speed (17K) FL
2000 C280 Sport is offline  
post #7 of 12 (permalink) Old 09-23-2010, 04:57 PM Thread Starter
BenzWorld Junior Member
 
Date registered: Apr 2008
Vehicle: 97 E320
Location: Mobile, Al
Posts: 24
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Send a message via AIM to stewmeistr
(Thread Starter)
Question

Ok, so I've been told that it is the blower motor relay. Where can I get one?
I recall that someone had aftermarket versions of this piece which were inexpensive. I looked at autohausaz and they don't have it listed (that I could find anyway).
Any suggestions or help?
Thanks,
Rob
stewmeistr is offline  
post #8 of 12 (permalink) Old 09-23-2010, 11:08 PM
BenzWorld Elite
 
Diesel Benz's Avatar
 
Date registered: Dec 2005
Vehicle: 222.132 & 221.122 & 212.025 & 906.633
Location: Europe
Posts: 10,322
Mentioned: 3 Post(s)
Quoted: 34 Post(s)
Quote:
Originally Posted by stewmeistr View Post
Ok, so I've been told that it is the blower motor relay. Where can I get one?
I recall that someone had aftermarket versions of this piece which were inexpensive. I looked at autohausaz and they don't have it listed (that I could find anyway).
Any suggestions or help?
Thanks,
Rob
Was it a W210 guru who told you it is a relay? Perhaps someone who is calling the regulator as a relay, it is often called resistor as in older cars but it actually is an electronic regulator (from the wiring diagrams it looks like a 1997 car already had this).

Your Parts Search Returned 1 Part(s)
Diesel Benz is offline  
post #9 of 12 (permalink) Old 09-24-2010, 11:15 AM Thread Starter
BenzWorld Junior Member
 
Date registered: Apr 2008
Vehicle: 97 E320
Location: Mobile, Al
Posts: 24
Mentioned: 0 Post(s)
Quoted: 0 Post(s)
Send a message via AIM to stewmeistr
(Thread Starter)
This was a PM to OHlord

"Hello,

I'm writing you today, because it was suggested that I speak with you regarding my 97' W210. My name is Robert Stewart and I have a problem with my AC blower not turning off.

The Fan speed will not respond to the push button decrease in the speed of the fans ( it is constant speed), however the compressor will turn off if you decrease the button to what would be the off position. The temperature controls work fine. No other problems with the control box, but the fans stay on even with the car off and the key out. This drains a battery really quickly!!!!!!

The car has no other problems, but this (right now).

What have I done to try and fix it?
It has been suggested that the blower relay is possibly bad. This sounds logical.
I did replace the little silver blower relay approx 2 years ago when it initially died, but I have not had any other problems with the ac system since and it has blown ice cold and strong since then. I have also replaced the ac control box in the dash thinking that was a likely suspect being that the back light had burned out a month ago. It was not. I have also tried pulling a couple of fuses, but I have not had luck thus far and don't really know which to pull. This has left me relegated to disconnecting the battery each time I leave the car for an extended period of time or else suffer a dead battery.

So, I am one step away from heading to the dealer and I'm asking your for help with the matter. Could it be just a simple blower or Fan relay again?
Thanks for your time.
Robert


Response from OHLORD:

"Either a faulty relay or the fan regulator.
Did you give the relay a tap to see if it opens if it does then replace it.
autohausaz.com carries the relay
Rob "


So I also googled this problem and came up with 3 other people that had the same issue and all were correctly fixed by getting a new blower fan relay. Thats why I posted the above "help, where can I get a new relay". I still don't know where another faulty relay could be other than located on the blower assembly itself. ?? Also I stopped into an AC shop and the guy said "blower relay under the glove box." SOOOOO, thats where I am.

Thanks for all help.
Robert

Last edited by stewmeistr; 09-24-2010 at 11:17 AM. Reason: poor grammar
stewmeistr is offline  
post #10 of 12 (permalink) Old 09-24-2010, 12:10 PM
BenzWorld Elite
 
Diesel Benz's Avatar
 
Date registered: Dec 2005
Vehicle: 222.132 & 221.122 & 212.025 & 906.633
Location: Europe
Posts: 10,322
Mentioned: 3 Post(s)
Quoted: 34 Post(s)
Quote:
Originally Posted by stewmeistr View Post

Response from OHLORD:

"Either a faulty relay or the fan regulator.
Did you give the relay a tap to see if it opens if it does then replace it.
autohausaz.com carries the relay
Rob "


So I also googled this problem and came up with 3 other people that had the same issue and all were correctly fixed by getting a new blower fan relay. Thats why I posted the above "help, where can I get a new relay". I still don't know where another faulty relay could be other than located on the blower assembly itself. ?? Also I stopped into an AC shop and the guy said "blower relay under the glove box." SOOOOO, thats where I am.

Thanks for all help.
Robert
Seems difficult to find the specific relay from the W210 wiring diagrams. One relay was named "fan relay" but in the diagram it was a relay for the horns, STF confirmed the latter.

There must be a relay if W210 experts say so. Would you mind telling us the exact build date of your car, there are multiple options, some change during 1997. Does the car have automatic AC or the basic one? It could be K40 related but the wiring diagrams are split so confusingly that it was difficult to follow where the power is coming to the blower regulator (and it seems to vary with the build date).
Diesel Benz is offline  
Sponsored Links
Advertisement
 
Reply

  Mercedes-Benz Forum > General Mercedes-Benz Forums > General Mercedes-Benz

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Mercedes-Benz Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











  • Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
     
    Thread Tools
    Show Printable Version Show Printable Version
    Email this Page Email this Page
    Display Modes
    Linear Mode Linear Mode



    Similar Threads
    Topic Author Forum Replies Last Post
    when do electric fans turn on? MBENZ1987 W140 S-Class 24 10-25-2010 01:46 PM
    I searched... Aux fans won't turn off at all. likedatyall W140 S-Class 10 07-25-2010 04:15 AM
    Auxiliary fans don't turn on The German W140 S-Class 14 06-16-2007 12:54 PM
    Radio does not turn off when i turn car off! help! fastmike99 Audio & Telematics Forum 3 09-04-2006 08:54 PM
    Auxiliary Fans Turn-On Temperature Sergio W124 E,CE,D,TD Class 5 06-08-2005 06:33 AM

    Posting Rules  
    You may post new threads
    You may post replies
    You may not post attachments
    You may not edit your posts

    BB code is On
    Smilies are On
    [IMG] code is On
    HTML code is Off
    Trackbacks are On
    Pingbacks are On
    Refbacks are On

     

    Title goes here

    close
    video goes here
    description goes here. Read Full Story
    For the best viewing experience please update your browser to Google Chrome