2007 Mercedes Cooling Fan Stuck on High

[mikeeustice]

Great video .love the euro diagnostics they dont publish much info. I had a Mercedes heater fan that was changing speed by it self .when it worked I compared the signals and notice the head unit wouldnt go flat line at 12 volts at high speed request to the speed controller used a test light connected to 12 volts touch the head unit control wire and high speed blower .dont worry about time I could watch your diagnostics for hours at a time😊😊😊

[arthurfricchione]

Keith that fan sounds like it is ready launch itself into orbit. Bring Stevie back I think there is water in the trunk. Seems like he had a great time. Thanks for the video ❤️

[SimplyDiagnostics]

Great intro :) Missing you and NY already mate. Had a real downer on me when I arrived back in the UK yesterday. Full steam ahead with my plan. See you in October and thanks again for the chance to work alongside you last week mate. You're awesome!

[txdm]

Had a similar issue on a Ford Edge only the fan wouldn't stay running after a body shop put an aftermarket fan on it. Found out only an OE fan would work properly on it.

[GhettoWagon]

That's not a problem its just on "Airplane mode"

[robinsonsmotorcycleandauto]

Great video and nice showing the power of having a quality scan tool and scope seperate. Can watch the request and what is happening in the circuit at the same time.

[weldingjunkie]

Things were just starting to “heat up” when you pulled out the pico then they cooled off lol thanks for sharing sir!... jay

[billyyoder]

Thank you Keith. Good job. I appreciate your videos.

[danjensen]

Hey Keith, these cars also have an issue with the driver in the engine control unit causing the fan to be commanded on high. What's weird is that it seemed to be losing the pwm signal command and would be stuck at an odd voltage.

[LMAutoRepairs]

Nice one Keith...
And you think 4 minutes video is too long...
Finished one yesterday.... 1h and 7m....🤦‍♂️
Thanks for sharing!

[nicknicu]

Cool issue, thanks for showing! 👍 OEM every time or one should find out who actually makes the part before the manufacturer stamps their name on it : save a lot of money that way..

[MrSoulstealer]

So it was the fan motor? Not the relay?

[ablackformula]

How do you determine the comm wire is going wonky from the fan module? Could the wire have a fault along the way? Would I have been wasting my time by cutting the comm wire and scoping both sides of it?

[scottpearsontoolsmore]

Great video thanks brother. I have never seen one want to run backwards unless you wanted it to or made it. Very interesting information. Keep up the great work see you in the next video thanks again brother

[stevenweseman]

It is always a matter of grace to post such videos but there was no explanation as to the root cause of the problem. Replacing the fan may be the correct remedy but what has caused this issue; in what manner has the fan failed and why? How does the car electronics control the fan? What aspect of the fan has failed?

[diymisfit_Mechanic_UDX]

OMG! you took almost 6 minutes LOL. awesome stuff there, it was worth it

[kellyr]

Keep up the German fish tank repair videos Keith.. Cheers

[erickfadeley]

How was the fan running with no request. Internally shorted

[dans_Learning_Curve]

Does this fan get controlled through an electronic relay, AKA large transistor, like the older Jeep Grand Cherokees?
The small current PWM from the ECU needs to be amplified by something.

[artsimannisto]

I have a 350 4matic e-merc, model 2010. Fan was loud, it started itselves at freezing point minus 5 celsius. Only turn power on, not started the engine, then after 10 seconds fan was self started and full throttle. I bought a new blower and it fixed it all. Blower ecu was a mess. Not cars own ecu.In fan there is its own ecu-unit. 450 euros plus first merc, w212 luxury limousine.and veeery exxpensive.Greetings from suomi finland.