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Need Pulse-Width-Modulation Frequency to W220 fan

11K views 37 replies 10 participants last post by  Witek_M  
#1 ·
Gentlemen, I'm the moderator on the W140.

I'm trying to hack one of your type of cooling fans for use in W140 M120 cars, so we can eliminate the no-longer-available :crying :crying magnesium clutch fan in the M120 W140 cars.

I could not find the fan diagnostic info of a W220. I check here, and no results..

StarFinder

and it is not here either :crying

STAR TekInfo

I just need the close approximate frequency of the PWM, and I will test it with a signal generator, and then program a Arduino chip to run the from the different resistance points from the engine block temperature sensor(s).

Thanks,

Martin
 
#5 ·
#4 ·
Hi @MAVA @Paul600600 ,

I am certain all ME2.8's use the same frequencies, I rebuilt my W220 Fan Shroud with a motor and controller from another Petrol Engined Benz with ME2.8 ECU :wink

HTH,
 
#8 ·
Thank you for the reply, but the W220 is a Large Fan that will fill all the radiator space.

In that case I can just get a W210 which is DC brushed reliable fan, and it is short an inch or two in width than the M120 W140 radiator.. I would run it with like the condenser fan works on W140 where it has three stages by having two low ohm resistors with three relays...

Martin
 
#7 ·
Because those are just on-off switches. As in full throttle....or nothing. That's a lot of amps.
With a PWM controller you can have the speed controlled the same as we do on computer case fans. A nice and slow speed increase up to only where it's needed. That'll not only use less power, be less wear and tear on the fan motor bearings, as well as generate less noise. And that is often the biggest improvement of this kind of upgrade on a vehicle.
Ever hear those loud diesel engines, like garbage trucks have? It's usually the radiator fan noise that's the loudest during those repeat accelerations.
 
#9 ·
Hi,

Personally I think it is always better to stick with the Tech on the car or upgrade if possible, certainly not down grade it :wink
 
#12 ·
PWM ;)
 
#13 ·
@MAVA, were you able to get any headway with this?

I'm starting to think that maybe I should investigate this avenue too for my E55 wagon... W220 fan is so much slimmer and narrower than W210 fan, but unfortunately W220 fan has the controller integrated into it whereas W210 has an external controller.

Even early W220 fan with external fan controllers are just as thick as W210 fan, so that's a bust too.
 
#14 · (Edited)
IIRC it was a C Class 600w Fan that I used on my SLK V8, the SLK as standard used a separate Fan Controller, but I used that wiring, (extended), and the C Class Fan was ultra thin as the actual controller is built into the Hub of the Fan Motor, works a treat with the PWM Signal from the ME2.8 ECU ;)

All I did was set the Fan Version Coding in the ME to 600W, but your 55 ECU will likely already be set to that ;)


That one says 400W mine is def identical but a 600w , you'll have to do some digging.

The Plug is same as W220, so can take out the wiring and plug to lengthen from a scrappy W220 like I did.
The plastic Shroud has plenty room to trim it so it is even thinner ;)

HTH,
 
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#15 ·
When you say the plug is the same as W220, how many pins did it have? Two pins, or three pins with the third being pwm?

I've thought of that too, of maybe just installing a 203 or 220 fan, bodge together something to work on the fan connector, and then extend the pwm signal that's going into the fan controller straight to the fan itself. After all, the pwm signal is something like 22-24 gauge wire, so clearly it's not exactly carrying lots of current. I just wasn't sure if the pwm signal to the external fan controller was the same as internal fan controller.
 
#16 ·
It has 4 pins / wires ................

Big fat Earth, Big Fat 60A Fused B+, thin Ign + and the thin PWM Wire from ECU.

Yes, the ME 2.8 pwm signal is the same internal or external controller ;)

You'd be very hard pushed, and have to look real closely at mine to decide it isn't a factory install, the main give away being my little aluminium brackets that fix it on to the Radiator Frame ;)







HTH :)
 
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#23 ·
I just need the close approximate frequency of the PWM, and I will test it with a signal generator, and then program a Arduino chip to run the from the different resistance points from the engine block temperature sensor(s).

Thanks,

Martin
From W220 ETM

Frequency and duty cycle.
 

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#26 ·
Yeah, there are a fair few, but after much research the one I got was the absolute thinnest MB Fan I could find, car is coming outta the garage later today so I'll try and find it, can't get it on lift, as I've a van stuck on that right now, but hopefully be able to find it without ;)
 
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#29 · (Edited)
Remember guys, this is not a "DC Fan" it is a "Three-Phase" A/C fan it is looking for A/C voltage. I toyed with one and I got no where with it with just 12v dc. Plus, my buddy wanted a solution NOW that moment, so I could not toy with it on my bench table where I could Inject a PWM from a function generator.

One can really power it from a Model Airplane Controller for electric model airplane where those controllers get into the Kilowatts of power. The input signal on those is 1mS to 2mS(1kHz-2kHz) pulse with a amplitude of 5v(logic level). On the model airplane controller the pulse width is what varies the motor control. The 5v is steady through the range.



The info Witek provided is reversed from the Model Plane Controller. There the Pulse is 10Hz, and the amplitude varies. In the real instrumentation world PWM is more common the model airplane method, but the 10Hz with varying amplitude is easily done on NE555 timer chip(50cent USD) for the 10Hz clock placed in astable mode, and passing through a comparator on a pot, or several pairs voltage divider resistors to get pre set speeds, and sending that voltage to unity-gain transistor- Easy peasy guys. Simple pulse electronics... or instrumentation electronics... to drive the factory MB fan Controller

Martin
 
#30 ·
@Deplore ,

The Fan on my R170 V8 is ....

600 Watt Temic

From W203

P/N A 203 500 16 93

Controller is built into the Hub of the Fan itself, and I cut the Wiring Plug and a long length of Wires outta the W220 S Class Donor Car, and spliced them to the Original 4 Wires that went to the R170's External Controller which was mounted on the Inner Wing ;)

I think this is a Chinesium effort but some good pics .................


HTH :)
 
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#31 ·
Well that makes it easy. That PN pretty much corresponds to any 04 to 09 C-class cars -- since here we don't get the gimped version that you guys get over there 🤣, that does help.

But I do have a question now.... from what you say, you spliced directly at the connector that goes into the external controller, and basically chucked the external controller out of the way.

Makes sense to me. What I'm not sure about is how to splice a 4/0 gauge wires together. I have soldered butt connectors with heatshrinks, but they're for max, maybe 10-12 gauge wires and aren't rated for more than 15-20A. 4/0 wire is a different beast, and I don't even know if there's a butt connector that big or if there's a safe way to splice them together without resorting to ghetto hacks.

And I don't want ghetto hacks.
 
#32 · (Edited)
And I don't want ghetto hacks.
:ROFLMAO: This is me ya askin' ;)

I got Butt Connectors that fit that size wire from a housing electrical contractor, and I cut off the plastic insulation, soldered them and used heat shrink over heat shrink 3 times, also I staggered the joints up the loom, taped up the connections over the heat shrink with a single layer of PVC Tape then covered in the MB style Cloth Tape :)

Ya cannae see it, and running the Fan flat out on DAS for 5 minutes it didn't even get slightly warm, also I upgraded the Pre Fuse on the R170 from 50A to 60A ;)

The splices are all inside this section of Wiring, the 2 studs sticking outta the Inner Wing are where the old Fan Controller was mounted ....



Butt connectors like this, cut off the plastic with a trimmer knife blade ;) ....


HTH :)
 
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#33 ·
lol, I'm not implying that you're bodging things shadetree style... just saying that I'm not a fan of twisting wires together and then taping them and hope for the best. Or using bolt and nuts and crimp them, or.... you know exactly which I'm talking about. I mean proper like, and once wrapped in felt tape it should be indistinguishable from factory harness.

Didn't know butt connectors of that size existed, found some on ebay. Just placed an order for these:


Should be fun to see what happens. Thanks again!
 
#34 ·
They're the kiddies ;)

See, there's a splice for every butt :unsure: :ROFLMAO:
 
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