radiator fan problem

[tekstil]

Hello,

Used search, but didn't find quite the same problem that i'm experiencing. Car is 92' S4 AAN. Well, the fan kicks in randomly, it doesn't matter if engine is hot or cold. Does this with ignition switched off. Sometimes it kicks in and runs for about 1-2mins then turns off. In one scenario it stays off, on other it starts again after it has stopped. Sometimes it can't decide whether to run or not and starts then shuts off immediately. It does it in winter (around -15celsius), in summer (+25 and so) and now when its around +12 outside. Yet it doesn't run constantly, at least my battery is not drained over night. Afterrun pump isnt working when it does this. But if i use jumper wire to connect afterrun switch terminals, both fan and pump works as it should. I have worked out so far that only way to stop it running is to pull relay No1 (Zeitrelais f. Lüfternachlauf) from relay box under the hood tagged as "214". Other relays dont have any effect on stopping it. From the looks of it i'd say it's the speed no1 that kicks in. I have swapped it with the other "214" relay that there is to control speeds - works exactly same way, so i don't think the problem is there. According to "Sjmautotechnik" 1st speed isn't controlled by the radiator termoswitch, so i'd rule that out too. Or i am wrong here?

Sorry if this post is long and confusing
Sorry if this is in wrong section, i'm new here
And sorry for my english.

[johne]

Sounds like your problem is a faulty fan after-run relay. It's the relay with "324" on it and although I don't know where it is situated on an AAN it won't be in the main fusebox but in another auxilary fuse box.

The 324 relay controls the radiator fan at slow speed 1 and also the after-run water pump and is known for going faulty and causing random running of the radiator fan.

I suggest you remove it and see if your problem goes away. You can do without it unless it's very hot outside or you use the car on a track until you can find a replacement.

John

[tekstil]

Thanks for the reply!

So i understand that relays "214" and "324" are connected to each other then, because when i pull "214" from pos1 in relay box, fan stops immediately. I don't get, why isn't afterrun pump running at the same time?

Anyway worth a try, i'll put "214" back and wait for the fan to start like a dumbass next to the car then and try to pull "324" and see what happens.

[johne]

Thanks for the reply!

So i understand that relays "214" and "324" are connected to each other then, because when i pull "214" from pos1 in relay box, fan stops immediately. I don't get, why isn't afterrun pump running at the same time?

Anyway worth a try, i'll put "214" back and wait for the fan to start like a dumbass next to the car then and try to pull "324" and see what happens.

The after-run relay, 324 has two, seperate outputs. One drives the after-run pump directly. The other output drives relay 214 which drives the radiator fan.

You can see the wiring diagrams on S2Central.net. AAN isn't on there but ABY is and it shows you how the relay is wired.

John

[tekstil]

Lol, already forgot about this. Problem was actually solved the day after this thread. As "johne" said it was 324 afterrun relay that was out of order.