Early W210 Blower Motor Regulator Replacement DIY Here...

[davey_90]

Thanks a million Tony. Got the regulator sent from Autohauz, the wiring was just as described. But the new regulator is much bigger, so some grinding and re-threading was required to fit it on the Irish spec fan housing. Anyway going perfect now. Cheers from Ireland.

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[roring]

Thank you for the great advice. I replaced my blower regulator following your instructions. I ordered the regulator from Autohaus, but I decided to go with the Kaehler (KAE) part number 1408218351, instead of the Behr.

My search results: Here are the two parts I found at Autohaus:



I thought I'd post my experience to let other know that installing the KAE part is almost exactly the same as installing the Behr part.

The only difference is the KAE part did not come with the two torx mounting screws, so I had to reuse the originals.

Also, the KAE instructions say not to add any thermal paste. The instructions say: "The surface of the KAE Blower Control Unit is already pretreated with a very high efficient propper (sic) amount of copper-heat-transfer agent, protected by a plastic cover." The package included a small cloth to clean the old thermal paste off the blower assembly

The instructions: With typos.



The shipping package. This blue box arrived inside a much larger brown cardboard shipping package. It was well packed, surrounded with brown paper to absorb shipping-shock and arrived in good condition:



Kaehler (KAE) part number 1408218351: The KAE unit with the plastic still covering the heat sink. When I was soldering the wires together, I accidently touched the plastic cover and melted a small hole in it. Fortunately, the plastic didn't melt onto the heatsink itself.



Cleaning the surface. I used the blue cloth provided to carefully clean off all the old heatsink paste.



The finished project. After reinstalling under the passenger side and turning on the blower full-blast, it worked great! Thank you for posting these DIY instructions, you saved me hundreds of dollars, and I now get full power from the heater and A/C.

[prostreethotrod]

i would like to say that the DIY here for the benz was the greatest money saver i ever had in a long time, it was easy to replace and only took 15 mins and saved $600....great pics and explained very well...keep the site alive
thx tony and now i'm back on the road with heat

[mashcigar]

I was experiencing the exact same problems, ordered the regulator from Autohaus last week and installed per these instructions on Thursday. Everything worked great for 2 days, and now today, I am back to NO blower. Anyone have any ideas??? I am wondering if my blower motor is bad, i.e. overheats maybe, and frys the regulator? I have run all of the AC diagnostics and no problems or error codes. Any thoughts?

[roring]

Hi mashcigar - You've probably already checked this, but whenever I do an electronics project that works for a while and then stops, I always go back and check my soldering job. Also, which regulator did you use?

[jaamb85]

After stressing over a huge repair bill for several weeks I found this article. How wonderful! I just ordered the Behr part 1408218451 and it should be here soon. One problem. I was reading over the pictures of the DIY and realised one issue.

I had my mechanic do a "Temporary fix" so the A/C when the two wires (larger white connector and smaller black connector) were connected would blow only full blast high. It would continue to blow even with the car off or with the A/C electronics off. It worked for a while until I was driving and I smelled melted plastic. The larger white connector was starting to burn up and one of the metal prongs came out. If i read this DIY properly I need this wire to be functioning... What should I do next?

thank you in advance!

Jason
1997 E320 90k

[Perry Hotter]

Tony, Greetings from Germany.

Well, had the problem too. Followed your instructions.
I used the Behr (original part# 5HL 351 321-021; which is the same as 140 821 83 51). Search the Behr-Website at http://www.behrhellaservice.com/Channels/Home/Home.jsp

Great stuff !!!!

[roring]

Hi jaamb85 - Yes, you need to keep the large white connector for two reasons: The most important is because it connects to the lead under the passenger side footwell. The second reason is the wires coming out of the connector are just the right size to reach the blower motor and regulator. Both problems can be fixed, but it will make additional work for you.

The first problem will be a pain to fix if you melted the connector on the car-side of the assembly. You can see from the photo below, the connector that comes with the replacement part is not the same. So you can't use that. You'll have to find a replacement that matches the original.



Hopefully, the connector on the car-side is still good. If you only melted the connector attached to the blower assembly, then you don't have to do any work under the footwell. All you have to do is find the exact same replacement connector (I'm not sure if you can buy the connector by itself) and include it in the project when you replace the blower regulator. Make sure the wires match.

Unfortunately, if you melted both sides of the connector, or if you can't find the exact same replacement, you are going to have to do some electrical work lying upside down on the passenger seat looking up into the footwell. Its already hard enough to disconnect and reconnect the existing wiring in that position. But having to splice in a new connector will be even harder. At least you don’t have to find the exact same connector.

This next part sounds obvious, but is critically important: make sure the replacement connector has the right number of electrical leads, and the same or better gauge wires. Make sure you exactly match up the wires coming from the car and going to the blower assembly to duplicate the original, otherwise you'll burn out your blower assembly.

The second problem seems simple but don't discount the importance of having wires that are just long enough, but not too long to reach their destinations. The original wires are just the right length so that the white connector from the assembly lines up with its counterpart on the car. If you replace them with wires too long or too short, you will also have a difficult time routing the wires around the blower to make the connection meet its counterpart. This will stress your splices, and the wires may interfere with the moving parts on the fan. So if you need to replace the existing wires, be extra careful to make sure they are as close to the same length as the originals.

Your DIY is going to be more difficult. I hope this helps.

[jaamb85]

Thank you very much for your help. I am guessing a good place to find one of these connectors would be a junk yard. I just hope i won't have to buy a new blowermotor, in which case I might as well just do the whole new upgrade. I am getting worried because I have never done anything like this before with all this wiring, etc. I know there is a Mercedes grave yard in northern florida. I could call them and maybe make a trip up there.

If anyone can think of any additional info I would greatly appreciate it.

Jason

[drnino]

Thanks Tony for taking the time to write this up. I just purchased a 1999 E430 and the air blows like it's whispering...and I have it on max. Lexrex was nice enough to forward me this post.

Here's my question: is a 1999 E430 a late W210? And if it is, I'm unsure how the process would differ.

Thanks!

[tony]

Originally Posted by drnino

Thanks Tony for taking the time to write this up. I just purchased a 1999 E430 and the air blows like it's whispering...and I have it on max. Lexrex was nice enough to forward me this post.

Here's my question: is a 1999 E430 a late W210? And if it is, I'm unsure how the process would differ.

Thanks!

I really can't tell you when the part changed over. However, if you can drop your blower motor with the instructions provided, and your blower looks like the one in the pictures, you can replace the regulator using this procedure. If your car has the newer upgraded version, then it will look different from the pictures and you can just buy a new regulator from any parts place. In that case, the regulator you need is part# 2108211551.

Good luck!

[ccmbduong]

My '96 E320 has a strange issue: when I use A/C in AUTO made, it blows higher velocity then NOT in auto mode , i.e. air blows to face and legs. Please advise what is going on. Thanks

[ccmbduong]

Tony and DIY MB owners: I think my '96 E320 has the problem that you mentioned , i.e. no change in air velocity from low to high setting, but when I switch to "AUTO" it seems like it blows a little bit higher... Sound familiar? I went into websites that you folks recommended but I could not find part numbers for '96 E320 , can you help? Thanks

[ccmbduong]

I email Mercedeshop.com and told them that my A/C fan is still running but seems to be low on velocity (from low to high setting) , I still can tell it increases in air flow ,but not "blow your hat off"... When I switch it from face/legs position to "AUTO" then it seems to blow more... Mercedeshop.com told me that it could be that the cabin filter is plugged (with 80K miles) ... Any suggestions and advices about this?

[ccmbduong]

Thanks to Mercedesshop.com who told me to replace the ACC cabin air filters first (I don't even know that they exist in my '96 E320 ). It took me less than 30 minutes (next time would be less than 15 minutes) to replace them. Now I can tell that air flow at different settings is much much better. Attached is step-by-step instruction with pictures, hopefully it would help someone. This is the first time that I replaced them after 78K miles

Enjoy

[Down South]

Just ordered my regulator yesterday! I had been having this problem for a few months now, now I know what the hell it is (LOL)

[ccmbduong]

I replaced air cabin filters (need to be replaced anyway) but I see only marginal improvement in air flow, so I think it could be related to the blower motor resistor/regulator. I contacted Autohauaz.com and they told me that part # is 2108211551 (for '96 E320) , but they also told me that I would need a blower assembly (# 2108206842) and a mounting plate/cover (#2108352740) .... Do I need #2108211551 only? or I need all three? Please advise. This is to replace the original OEM part. Thanks

[ccmbduong]

Now I am confused. I read on another MB website and someone mentioned that buy the blower regulator for W140 and use it in W210 because they are the same size, except wire length is shorter... Can someone help me out? What should I buy to replace a blower regulator for my 1996 E320. Thanks

[ccmbduong]

(I removed my blower today and ordered the parts from Autohaus. It took me about 20 minutes to remove, thanks to your instructions. I will post after the installation. I am sure I will have success soon!)

Iwhite: I believe that you have a '96 E320 just like what I have. Please tell me which part # that you replaced (Blower motor regulator only? or do you have to buy blower assembly and mounting plate as stated buy autohauaz.com). Thanks

[handyman john]

Tony,

Just got the part and did this repair this evening. Thank you so much. It works beautifully. My indie machanic wanted $1000 to get this problem solved. (new Blower = $450, voltage reg = $250, balance labor). Thanks to you and the folks at autohausaz, I am back in business for $163.63 !!!

A few questions for the group:

1) I noticed a lot of carbon dust from the motor brushes. Anyone ever need to change the brushes on these W210 blower motors ? Tough job ? Where to get the parts. Mine is working fine, but its always good to know.

2) Looks like the original post is a year old. Is everyone's new regulator holding up well ?

Thanks for helping me save my family $836 !

[ccmbduong]

Yes, I just ordered the KAE part from Autohousza.com for $163.63 . It should be here next week and I should be back in business again. Thanks for Tony's write up and input from all of you. This is the power of internet and thanks for sharing info

[tshaw]

Well, add me to the list of those who finished this DIY. Tony, the directions were great! Saved a bunch of money PLUS my wife will probably quit laughing when she catches me on this site!

[ccmbduong]

Got mine done today, took me about 1 hr (I just took time and made sure that I won't make mistake cutting a wrong wire). Now it really blows my hat off. Thanks for Tony's instruction and input from all of you. The KAE unit is made in Germany BTW

[ccmbduong]

forgot to mention that I used crimp (sp?) connectors instead of soldering and it works very well

[tony]

Hi guys:

I'm glad I've been able to help everyone out. I won't be checking the board much anymore since I sold my E. You can catch me on the e38 board on Bimmerboard.com where my username is Imolatony.

Oh and tshaw, I happen to live in Norcross too. Small world, isn't it?

Cheers!