KAROZZA

My radiator cooling fan seems to have decided it needs a vacation & only works when it feels like, which is quite rare nowadays

Being hands on & ready to tear it apart; was wondering if this is repairable rather than replaceable, hopefully saving a small fortune!?

Any suggestions, links etc....will be appreciated.

Alternatively, the best place to buy online?

Cheers.

KAROZZA

Has no one replaced this?

Ghostty

Personally I haven't. But I'd start by checking everything:
is a fuse connection problem? Wiring connection problem?
is the actual fan acting up? Is it temperature related? How much is the cooling fan itself?

although it might be not complicated at all, I'd still check before throwing parts at it and if you have an actual SDS handy or a trusted indy who could check for codes - that would be even better.

Regards and keep us updated,
Ghostty

KAROZZA

Already gone through those & checked with my Indy who confirms the symptoms lead to a fan failure; apparently he has come across this a few times on the SL.

Have now taken the fan out & stripped the module but nothing visually looks faulty.

Ghostty

Oh, if so then might as well replace it. How much does the fan sell for? Electric issues are impossible to visual track it))
I had much more fun with the Ignition module (EIS).

KAROZZA

That's it, if no-one has managed to repair; would like to know where best to buy on line. OE is most probably expensive, so maybe others have used after market; I think Topaz?

I have seen some one take it apart & found a blown IC, but mine seems to be intact.

Rudeney

Power to the fan is through a large 100amp mega-fuse on the pre-fuse panel under the passenger side dash. If it's blown, you'll get no operation at all.

The fan has an integrated controller that varies the speed based on signals from the ECU. If the controller fails to get a signal from the ECU, then it defaults to high speed. If it does not operate when it should, or operates erratically, it could be a bad controller or a bad motor. The fan itself is sold as a complete unit, though there are some aftermarket suppliers that sell individual parts. Another option is a used fan. Unfortunately, the fan application for your car is only used on AMG S, CL and SL models so a new part it likely to be expensive and difficult to find used.

KAROZZA

That is absolutely correct. If I do not manage to repair, I'm looking at the next step.

I have concluded the controller, which is separate & not integrated in the fan motor, faulty as the fan occasionally did come on & does not feel jammed. None of the other symptoms apply. Maybe will try to power it up on the bench but not yet entirely sure which are the correct wires.

Buying used doesn't strike me as wise due to them mostly being old now & prone to failure just as mine. Unless the owner could confirm it was a recent replacement.

So, would like to find an after market controller if possible? Or, maybe a used one as may not be an expensive gamble!?

Ghostty

Well, just like they say, it's all about the money If the fan is $300+ and you can find the controller for $50 - it makes sense. If the fan is $150 and the controller $50 - i'd get a new fan.

Idk if it would work, but i'd see if you can bypass the controller and connect the fan directly to power to see if it fails or not. That might help you narrow down the issue. And any way around what year is your SL? i can't say it's that unusual for 10 year old parts to fail. So if you replace it for another 10 years - it might give you peace of mind. Just some food for thought.

KAROZZA

Ghostty

I would say it's both - age and complexity of the car. Things like that will happen and there's nothing to do about it. Sorry to hear you had more to deal with it. Mine is 2005 and I had little work on it.
And it's not very cheap to repair because these cars, as you said, were the flagship car of the company, so they used most advanced systems.

how much is for a used fan?

KAROZZA

KAROZZA

So, back to the challenge....stripped the controller module to pieces & took it to my tech to have a look.

it does have 2 ICs that have shorted. All 6 on the board are the same; B80NF0 made by ST

Problem now, I cannot find it locally; any suggestions where best to buy on line?

Either that, or anyone have a defective controller I can take the components from?

LGAFF

https://www.ebay.com/p/2205000293-Mb...2702020&chn=ps

I bought this one and no issues..... great company based here in Illinois

ponchik

had the same thing with SL600. Fan died after an engine wash.
Everyone told me that these control units cannnot be repaired. I still have a defective controller, but i'm not sure it will be useful as a donor.

KAROZZA

Would like to try to source from Europe as shipping that size item from US would be quite expensive.

KAROZZA

It might be of use; can you check the part number on the module?

885 000 764

It should be a TEMIC 850W

ponchik

It's in my mechanic's shop, so it can take time.

As for replacement, there definitely is BEHR (which is the same as OEM) and some chinese noname one. As i recall, this May i paid around 600 USD for BEHR and chinese one was around USD300

UPD. As for replacement we have here BEHR 8EW351040091 Polcar 502523W3 and W2 and Termal 404004U ans S. For Polcar and Termal you should check the power output of the fan.