My climate control fan has been acting strange lately, I can control its speed from intensity 1 to 5, but there is no increase in speed for intensity 6 and 7.

Is it a DIY thing or does it need to go to the shop?

Thanks in advance for any advice.

Simple is a relative term..the job is simple for any MB tech. Takes less than 40 minutes.

However on that model replacement might REQUIRE replacement of the blower motor as well!!

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Thanks for the reply M.B.Doc, I found a good post over at BenzWorld.org showing easy step-by-step instruction on how to replace the regulator with the one for the W140 S420, instead of replacing the whole blower assembly.

The procedure appears simple and anybody with reasonable handy skills sould be able to do it in an hour or so. I'm very familiar with soldering, and am mechanically inclined as weel, so I'm confident I can handle it.

The only question I have, the Bosch regulator for the W140 sells for $211 at the AllPartsExpress site, compared to $318 for the Behr regulator. Is is worth to pay the $90 difference, or are they pretty well equal in quality?

I also saw one sold by DeutschePartsUSA on eBay, "manufactured by Hamburg Technic in Germany, with a 1-yr unlimited miles warranty",for as little as $71 including shipping. Sure smells fishy, but does anybody here have any experience with that manufacturer?

UPDATE:
I have succesfully installed a regulator for a W140 in my E320-W210 (see picture showing the spliced wires). It took about 1 hour from start to finish, and can be done without removing the blower unit from the car, but it's tight down there, so it just requires a bit of flexibility. Even though the fan still appears to max out at setting #5, it is much stronger now at all speeds, and well worth the effort.

Attached Thumbnails

 

thanks for the info and picture. This is the first evidence I have seen with more info AFTER the mod.

Can you share more about where the old reg was mounted and how the new one is mounted? Are they similar is design, therefore mounting is the same?

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83 300TD (need rear wiper assembly dead or alive)
84 300SD Daily driver
85 300TD almost 400k miles and driven daily.
98 E300D *sold
86 300SDL *sold and made flawless 10 hour journey to new home.

The new regulator fits without any problem where the old one was.
Mine is still working without any problem since I did the replacement.
Good luck with yours.

I went ahead and bit the bullet and got the fan/reg/cover updated parts locally with a discount through a friend. The 'hellacious' summer heat is just hitting us and I prefer that my wife and daughter are in a reliably cooled car. Combined with an a/c system check up, the climate control is working better than it ever has. I can hop into the car after it has been backing in the sun and have near instant cold air. Perfect.

Worth every penny.

__________________
83 300TD (need rear wiper assembly dead or alive)
84 300SD Daily driver
85 300TD almost 400k miles and driven daily.
98 E300D *sold
86 300SDL *sold and made flawless 10 hour journey to new home.