DubYah140

Well, after much research on the web I was able to determine that my extremely low fan speed for the HVAC was more than likely due to the blower regulator. One thread suggested Arizona Autohaus was a good place to purchase, so I did. It came in, and as I went throught the replacement I ran into an issue.

Well, maybe.

Here is a photo of the original blower regulator installed.



It is a BOSCH part, the number on it is 9 140 010 099 and says Made in France. The other number (at the bottom) is 90.943.02.225 (not sure what this number is).

Here is a photo of where the blower regulator was removed from. THere is still some residue on the mounting surface that I know needs to be cleaned. The size of the mounting surface is about 1.5" square.



Now, here are two pics of the new part. It is a KAEHLER, Part# 3.701.300, Made in Germany. The Autohaus Arizona Part # is 140 821 83 51. The copper surface is already pretreated with the proper amount of heat transfer agent.





My concern is the size of the mounting surface on the new part. It is the same width as the original, but twice as long (approx 1.5" x 3"). The mounting surface on the blower (1.5" square) is raised from the blower about 1 mm. The holes for the torx screws are in the same location and line up with the blower itself.

Are these two parts interchangable? Will I have any problems with installing the slightly larger mounting plate to the smaller mounting surface?

Any help is greatly appreciated. I would love to have the HVAC working properly in my big black beauty.

vinamg

Yes, the regulators are interchangable. The base was redesigned to better dissipate heat when blower is turned down to a lower speed.

BTW, I think the BEHR regulator is the best one, but it is slighly more expensive.

Rod Spohn

DubYah140 - That is the same part I used from Autohause, it worked great and everything fit. And yes living in Arizona I was glade to have the fan speed back. After all the hastle figuring aout what it was, I was amazed at how easy it was. Thanks again for the info from this forum.

tbilisi79

I got my regulator from them and it works as it should.
Shame on MB for making such a bad designed part.

DubYah140

Sorry I haven't replied yet. Even before I got responses, we just installed it to see if it works. Well, as you all have posted.. it worked like a charm. We went from blower speed equivalent to a Chiuaua fart to a Category 3 hurricane coming from the dash. Amazing difference!

algevor58

i need helpppppppppppppppppppppppppppppp WHER IS THE HEATHER BLOWER IS LOCATED ??????????????????????? I HAVE 1997 S500 AND MY BLOWER DOSENT WORK I DONT KNOW WHATS WRONG WITH IT DOSENT MAKE ANY NOISE U CANT HEAR THE FAN BUT CLIMET CONTROL IS WORKING FINE BUT NO BLOWER I WANT TO KNOW WHERE IS IT LOCATED........................................... ...

benica

Don't use cap letters....

blower motor is located under the plastic cover...under the hood...passenger side...against the firewall. About 10 or so screws to remove.
Could be the resister or motor just like the 1st post here.

vgo8888

The part that you are replacing is the power transistor. The real cost of it is $2-3 dollars. What you are paying is ownership of Mercedes. If you can figure out the original part number of the transistor (could be IC power regulator as well of similar cost) - you can just de-solder the wires and solder the new part - where 3 terminals are. The larger surface is to have better cooling. Obviously, some third class Mercedes Engineer has underestimated the termal difference and heat transfer from that transistor to the housing of the blower. They are correcting this mistake in this new part.
I would purchase the cheapest regulator I can find because the transistor quality is the same. You are probably getting a cheaper connectors - but you can re-use your original ones if you want. This is my 5c to this discussion. (do not worry that it is made in France. If German engineering is that good - you would not need to be replacing it - it is their engineering mistake)