Fan stays on, even after car turned off - BMW Forum

Spinn · 01-15-2010, 05:13 PM

I have a 97 540i and love the car. The problem is the fan stays on after I turn the car off and this kills the battery. I have the heat and ac both turned off but once in a while they spontaneously come on and stay on a few minutes or more then stay on when I turn the car off.

Any ideas?????????

witeshark · 01-15-2010, 05:25 PM

It could be a sticking switch or relay. You may be able to find them at Realoem.com

Spinn · 01-15-2010, 05:30 PM

Im kinda clueless do you know which switch or relay it might be?

Thanks

witeshark · 01-15-2010, 05:40 PM

Most likely it's a thermostat swich that turns the fan on at a certain temperature. There's usually also a switch that forces the fan(s) on any time the A/C is turned on.

Spinn · 01-15-2010, 06:01 PM

Thanks now I have to find that, I said I was clueless. Kinda odd considering its been in the 30s here that the AC would come on. thanks though.

witeshark · 01-15-2010, 07:07 PM

Well a bad switch wouldn't care about the A/C on or off or about the temp...

425e39 · 01-15-2010, 07:16 PM

I have the same issue. Very frustrating, the thing has a mind of its own. My mechanic says it's the final stage unit. You might want to look at that. I bought one from eBay to put in myself.

Spinn · 01-15-2010, 07:32 PM

and that did not fix it?

425e39 · 01-15-2010, 08:15 PM

I don't know yet. Just got it in the mail today. Just in time for weekend tinkering. He was certain enough to offer to order the parts and schedule me in. I told him I'd take a crack at it. In the past two weeks I've done valve cover gaskets, water pump, oil separator, and yesterday, the cooling system. Oh yeah, three weeks ago, a fan clutch. He has enough of my money for right now. Love the car and the drive so what can I do?

Spinn · 01-15-2010, 08:17 PM

Im with you and I hope it works. Mine has 150k miles and is the best car I have ever driven.

Mind if I ask what the unit costs, approximately.

425e39 · 01-15-2010, 08:54 PM

Same here. Owned a 733i and a 525i, but the power in the 540i is incredible.
I paid $38 and change with free shipping. If you go that route be sure to check p/n at realoem.com. My '97 has 133k, my '99 has 158k. Wouldn't trade either of them.

Spinn · 01-15-2010, 09:05 PM

thanks but I cant find it...I really am cluless, have a link?? you will be in my will if you do. thanks

425e39 · 01-15-2010, 10:31 PM

No link, but go to eBay.com and type e39 final stage into the search. They'll come up and you just have to be sure to pick the right one. Very easy!

witeshark · 01-15-2010, 10:57 PM

Quote:

Originally Posted by Spinn

thanks but I cant find it...I really am cluless, have a link?? you will be in my will if you do. thanks

Have you tried the realoem.com site?

Spinn · 01-15-2010, 11:45 PM

thanks 42, found it $38 like you said. Now I have to figure out if I can install it.

shark I could not find it there.