E46 Cooling fan wouldn't stop...and then it did.

[blee]

So my friend's '99 323i developed a problem earlier today where the cooling fan would remain on after turning off the engine. It eventually ran down the battery, so I came over to jump start the car. I got him to drive around the block, then to park it in the garage to see if the fan would stay on this time. He switched off the car, the fan kept running, and then smoke came pouring out of the engine bay. By the time I could unhook the battery, the fan stopped on its own.

From what I can tell, it looks like there's some kind of control module attached to the radiator fan. The plastic cover appears to have a big hole melted through it now. I should be able to replace the control module, but I don't know whether it comes attached to the fan. Any ideas?

[elbert]

Wasn't there a big recall for fan switches catching on fire? Don't know if this car would be part of that, though.

[blee]

Wasn't there a big recall for fan switches catching on fire? Don't know if this car would be part of that, though.

There was, but I don't think this car qualifies. It's a '99, and IIRC the recall is for 5-speed cars produced in 2000. Grrr...

[rumatt]

Damn, that sucks.

What was the smoke? Melting plastic?

[Nick M3]

March production '01 cars.

Yes, I had one.

[elbert]

Wasn't there a big recall for fan switches catching on fire? Don't know if this car would be part of that, though.

There was, but I don't think this car qualifies. It's a '99, and IIRC the recall is for 5-speed cars produced in 2000. Grrr...

I'd still ask the stealer, couldn't hurt. Maybe your friend has an end-of-year production which might get covered? IIRC that recall got expanded a couple weeks after the initial recall.

[blee]

They're going to call the dealer to see if they're covered. Would be nice. It looks like the fan is really easy to remove, but obviously free is preferable to not free.

I can't get a good look at the thing without removing the fan, which I couldn't do last night because they didn't have any Torx drivers around (what's wrong with people?!). But it looks like the plastic cover to the little control box is toasted. I saw a drop of molten plastic on the AC pulley, and it looked like there was a big hole in the cover itself. I don't know if the fan is sold separately from that little module....I kind of doubt it.

[Josh (PA)]

I went through 4 fans during that recall period in my '01 325i. It was the "aux" fan control module that would burn out and cause the fan to stop working and in a few cases catch on fire. I believe the bad fans were made by Seimens and the replacement fans were Bosch. There's a boatload of info in the toadfly archives if they are searchable yet

The thing that always puzzled me about the recall was *I think* both manual and automatic cars share the same electric auxiliary fan (I could be way off the mark here, but this is what a service guy told me during one of my many visits). The difference was the automatic cars also had a mechanically driven fan that ran constantly. If this was the case, why wouldn't the auto cars had burnt out fans too?

[ZBB]

March production '01 cars.

Yes, I had one.

Me too... and then they replaced fan was recalled for the same thing....

[Doug]

Sounds like the relay is sticking. Pull it off and smack it on your hand or get a new one

[The HACK]

If this was the case, why wouldn't the auto cars had burnt out fans too?

If I'm not mistaken, the aux. fan on the auto is different from the aux. fan on the manual.