My car was working perfectly fine, the battery kept on dying because the car wasn't driven in two months, I replaced the battery and when I turned the car on, the fan turns on right away and stays on until I turn off the car and my climate control buttons are not working, Its a 2013 Mercedes C250 Coupe, I checked the 7.5 amp fuse under the hood, I believe it was fuse number 12, but the fuse seems to be fine, is there any other fuse that I should check? I switched back to my old Mercedes battery to see if my new battery was the issue and still the same thing. Everything else seems to be working perfectly fine, the fan stays on and my car maintains a normal temperature . URGENT HELP

 

 

Bump.

Just replaced my dead battery and ran into this same issue. Climate control will not turn on and radiator fan starts immediately and will not turn off until I turn off the car.

 

 

I like to share the info but not sure if it is the same case:
My Infiniti SUV had a bad blow motor control unit, not sure sure if it an exact name. After 16 years one day it suddenly stopped working normally. A/C fan is always at its max whenever I started the car. I bought a cheap one online and installed it, but it only worked one day then it happened the same way. I bought another 'cheap' unit from another online place and it has been working perfectly since like four months ago. I tried adjusting fan speed, temperature, on and off , etc., and it is working solid. OEM unit is like $120 and my 'cheap' unit is about $25.

 

Unfortunately it isn't my A/C fan. It is my cooling fan on my radiator that is on constant high. Also, the climate control module has no power at all (No red light above the 'off' and none of the buttons work). I'm assuming this happened from trying to start the car with a low/dead battery. I replaced the battery but not sure if something needs to be reset or what component might have broken. Does anyone have any idea where to look (besides the dealer).

 

Did any of you found what was the problem?

 

This happened to me when I had my windshield replaced. Brought it to the dealer and all it was, was a blown fuse. The windshield tech was trying to be a nice guy and attempted to re-wire my dashcam camera back without telling me and apparently blew a fuse. Can't tell you which one though since I don't know. Happy hunting.

 

 

Unfortunately I had my car at the dealer while you responded so I had to pay $200 for a diagnostics test just for them to tell me the same thing you did.* AC control unit bad (and a few other unrelated things )

I know I should be matching the HW # and the SW # when buying a new one from Ebay, but should I care about the KW # as well?

 

I just wanted to follow up here. Dealer wanted to charge $1,000 for new climate control and install. I bought it on Ebay for $55 with matching HW and SW # (KW did not match). Quick install and everything worked like new. Thanks everyone for the help.

 

I am having the exact same problem! W204 2011 C300. It was -14C bitterly cold this morning, started the car fine and immediately the engine A/C fan switched on full speed VERY LOUD and would not stop until the engine was shutoff. There are no climate controls lit up, ie. no fan controls, no temperature dial, no rear window defroster, no defogger, no OFF button, no Auto, etc. The entire panel is dark.
Very dangerous to drive in winter, the windshield interior and side windows fog up with moisture and not vented and could cause a collision!

Can someone guide me to which bank of fuses would be suspect? It may not be the climate panel but a fuse. Thanks... freezing in wait....

 

Those were the exact same symptoms as mine. As stated above, you can check fuse 12 under the hood if you want to waste some time but its most likely going to be the climate control unit.

 

Update: I checked every fuse in the car with an ohmmeter and all passed. Then I wiggled each fuse to ensure connectivity, moved the car to a sunny location to warm it up (LOL it was only a few degrees warmer, still bitterly cold). Then cycled the car on and off a few times and waited to try again. Then the climate panel functioned again. Steps: I ensured everything was off (the backup cam/nav screen was closed, no radio, no lights, no wipers, door closed) and slowly turned the ignition from position 1, waited, then pos 2, and then the climate control console lit up and worked fine. Finally full defogger + defroster + heat + fan controls + temp controls + ac, etc. all worked fine and the insanely noisy loud engine fan was not on.

Seems like the climate console is intermittent and on the way out - like you said... shall I purchase a new one from MB or is a used one from a newer model W204 safe to use? (ie. more reliable and perhaps an updated engineered version on newer W204's?).
Thanks!

 

Im 3 months into my eBay climate control and have had 0 problems running it essentially every time I’m in the car since I’ve in the north east. $55 on eBay vs $1000 from dealer is kind of a no brainer in my opinion. Install is very easy too.

 

HELLO there!

Having the same exact issue. Put a new battery in yesterday, everything works but the climate control. Please advise.

 

Get a new climate control unit from Ebay. Read above for more info.

 

Is there maybe another fuse other than 12 I can check before ordering? Ac was working perfectly fine. The car sat with a dead battery for 1 day.

Thanks!

 

Did you have to have it programmed?

 

Hi! I am having the same problem on mine..what does HW and SW mean? I have looked at used panels but I'm scared they might not work with my car even tho they appear to be the same. And did you have to have it programmed?


ALRIGHT GUYS I FIXED IT!
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Thanks for the information and discussion. It has been helpful and instructional. I guess HW is short for hardware and SW is short for software, but that is just my guess. I don't have a guess what KW stands for.

Although my car is not W204 but X204 (2012 GLK 350), it is experiencing a very similar problem, as in that 1) Climate Control Unit has no power, no light, and no response after starting the car; 2) engine cooling fan turns on a few seconds after starting the car and remains on (it blows out cold air from the front of the car); and 3) first happened about two months after replacing the car battery and remained faulty. The difference is the 7.5A fuse for climate control system was blown and after replacement the new one was blown again as soon as starting the car.

Took to a mechanics briefly and he turned on the car and had a look at the climate control unit and the engine cooling fan under the hood without further detailed diagnosis. He thought it is mostly likely caused by a short in the Climate Control Unit because only the 7.5A fuse kept being blown, not any other fuses with a higher current rating.

I took the Climate Control Unit out (by largely following the Pelicanparts tutorial for W204, with some modification since mine is X204) and used a multimeter to test the electronics with a new fuse (without starting the car). There are three plugs at the back of the Climate Control Unit. When the left and right plugs are plugged, the fuse resistor reading (while sitting in the fuse box) was normal (0.1-0.2 ohm). However, the reading increased to 1.4-1.6 ohm as soon as the middle plug (the one with 16 pins) was plugged in.

Could anyone suggest whether this indicates a short or a problem in general with the Climate Control Unit? Any other comments, insights and suggestions are also welcome.

 

Could you find what was wrong with it? mine is also doing the same and i did replace the AC unit still nothing

 

Good anyone find what the problem was? my C200 CDI 2012 did the same thing now after we jump started it

 

Where you able to fix your problem on 2012 glk 350? Having same problem

 

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What is the SW hw thing u guys are talking about. I am having the same problem right now.