gn3

I've noticed my car overheating in traffic. I've narrowed it down to the electric fans in front of the radiator not coming on. I've tested the fans - ok. Checked all the fuses. No diag codes on the climate control. My next guess is the relay. Does anyone know where it is?

Pancho

As another example of pointy headed Teutonic needless over-engineering, the cabin blower/fan regulator is linked to the electric fans in front of the radiator/condenser. If the cabin fan regulator is bad, then the external electric fans don't come on, and your aluminum engine overheats. Brilliant, huh? Cabin fan regulator goes, and your engine burns up. And to think, the Germans used to built war machines. I guess the French can sleep at night.

Here's a link to my website where I have a pictorial "how to".

Best of luck.

http://www.panchogun.com/FVWebPhotos...bin-Filter.jpg

gn3

Wow, where is the logic in that? Is there a way to test the regulator before I order a new one? Is there an aux fan control unit or relay somewhere?

cherylsbo

Just as gn3 my 2000 CLK430 Cabr was running hot when I would idle for a while and the two aux fans on the front of the car never came on. Temp got up to around 110. If I started driving the temp came down to normal (between 80 and 90). I replaced the blower motor regulator (and also the cabin air filter while I was down there). I ran the car and then let it idle for a while, temp got up to 105 and the fans still didn't come on, any ideas what I need to try next. I can't believe that both fans would go out at the same time. By the way the A/C is working fine.

gn3

I think the blower regulator is for the interior air flow. My problem was the aux fan regulator (it may have another name) it's located around the bottom of your radiator on the driver's side. You can trace the fan wires going to it. The part was $160 from what I remember and the mechanic told me that it's had to be programmed so I paid $60 for the labor but I think that's BS.

Meanwhile keeping your heat on MAX HOT will help you get the engine temp down.

You can also try the diag https://mbworld.org/forums/clk-class...-features.html
Sensor 20 should show a high value when the fans are supposed to kick on meaning that the regulator should be getting power if you want to test for voltage at the connector.

cherylsbo

I was going on what Poncho had said in his post, "the cabin blower/fan regulator is linked to the electric fans in front of the radiator/condenser". He was talking about the one under the passenger side dash. I saw this on other posts as well and knew it would fix my problem but don't think it has. I haven't heard about the aux fan regulator that you mentioned but I will check it out as well. Thanks.

SoCalw11w123

or Find a Independant Mechanic that has the Multiplexer and software to check the ECU settings.

My ECU programming was still STUCK as "transport mode" and tuning was set at 89 RON and both fans were DISABLED in the programing.

My independent Tech was able to reprogram the ECU and re-activated the fans, and reset my car to 91 craptane, as 93RON is not available in California....

I was able to see this work done LIVE in his shop.... I have experience with the BMW carsoft and played with the GT1.

maverick5.0

on my car the ac/freon was low... and the fans did not work... took the car to the ac shop and they work now. this is on 99 clk430

cherylsbo

Well it turned out that it was my fan control module that was bad. Replaced it and the two fans in front of the radiator work like a charm.

dlbehrns

And where was that module located please?

cherylsbo

I actually took it to an import shop to have it replaced, but I believe it's located under the front bumper, drivers side. You should be able to follow the wires from the fans to the module. The shop charged me $185.00 for the part and 2 hours labor, plus had to have some connectors that were burnt, total bill was $408.00, I'm sure I could have saved some $$ if I would have done it myself but I couldn't get to it and knew I needed to get the car in the air to do it so I opted for the shop. I first replaced the blower motor resistor myself thinking that would fix it but it didn't. Anyway it's fixed and we cruisn'.

knweran

dear
i had earlier the same issue for my CLK230 1998
the cooling fans located front of the radiator were not working .suddenly stopped also it affected the compressor as not engaging also. i have tried many things . after searching here in MB world, i found some helpful ideas that helped me to tell the tech about the problem and i had solved the problem by only 35 USD . and by W40 oil .
cant imagine that as we found the Data Cable going to Sensor no 5 located under the front fog light left side . loose connection and one cable full of corrosion , just cleaned ,and no more issue ..
working normal . AC is normal and cool . and compressor is engaging

hope this will help in future and not to let ppl fooled in case of maintenance charges .
here is the sensor

ABO HADI

good day
your reply to the subject seems to be the best and cheapest.
I have the same problem in my car but I don't know if these wires are easy to be seen and replaced?! or I have to remove the front bumper to to that!

thnax

coo1guy_tv

Not working

00-430

Here is a version of the link from the webpage as it was in 2011.
https://web.archive.org/web/20111018...bin-Filter.jpg