# Blower fan runs slow/stops **URL:** \ **Category:** Maintenance/Repairs\ **Tags:** bmw, 335\ **Created:** [June 6, 2021, 3:06pm UTC](https://community.cartalk.com/t/blower-fan-runs-slow-stops/177275 "2021-06-06T15:06:51Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![Pcarlisle62\_175375](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@Pcarlisle62\_175375](https://community.cartalk.com/u/Pcarlisle62_175375)\ **Post date:** [June 6, 2021, 3:06pm UTC](https://community.cartalk.com/t/blower-fan-runs-slow-stops/177275/1 "2021-06-06T15:06:51Z")
My blower fan does not run on high, only 3 bars. When I come to a stop, the fan goes off completely, briefly. Sometimes after running for awhile, it will come on full speed. Thoughts? ---
**Author:** ![COROLLAGUY1](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/corollaguy1/32/7575_2.png) [@COROLLAGUY1](https://community.cartalk.com/u/COROLLAGUY1)\ **Post date:** [June 6, 2021, 3:09pm UTC](https://community.cartalk.com/t/blower-fan-runs-slow-stops/177275/2 "2021-06-06T15:09:20Z")
Replace the fan ---
**Author:** ![davepsinbox\_157004](https://avatars.discourse-cdn.com/v4/letter/d/73ab20/32.png) [@davepsinbox\_157004](https://community.cartalk.com/u/davepsinbox_157004)\ **Post date:** [June 7, 2021, 1:22am UTC](https://community.cartalk.com/t/blower-fan-runs-slow-stops/177275/3 "2021-06-07T01:22:48Z")
I’m not a mechanic but it sounds like the fan motor is responding to variations in alternator output, i.e., greater output when the engine is turning over faster as opposed to idling. You didn’t say what year your 325 is but either have a dealer or a good independent mechanic look at it, depending on whether it’s still under warranty. ---
**Author:** ![Scrapyard-John](https://avatars.discourse-cdn.com/v4/letter/s/f6c823/32.png) [@Scrapyard-John](https://community.cartalk.com/u/Scrapyard-John)\ **Post date:** [June 7, 2021, 2:52am UTC](https://community.cartalk.com/t/blower-fan-runs-slow-stops/177275/4 "2021-06-07T02:52:25Z")
Next time the fan stops running, bump it with your fist. If it starts running again, the contacts inside the fan are worn and it needs replaced. ---
**Author:** ![Pcarlisle62\_175375](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@Pcarlisle62\_175375](https://community.cartalk.com/u/Pcarlisle62_175375)\ **Post date:** [June 7, 2021, 3:35am UTC](https://community.cartalk.com/t/blower-fan-runs-slow-stops/177275/5 "2021-06-07T03:35:10Z")
Thanks, will do if I can figure out where the fan is, lol. ---
**Author:** ![Nevada\_545](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nevada_545/32/41232_2.png) [@Nevada\_545](https://community.cartalk.com/u/Nevada_545)\ **Post date:** [June 7, 2021, 3:57am UTC](https://community.cartalk.com/t/blower-fan-runs-slow-stops/177275/6 "2021-06-07T03:57:18Z")
> [@Pcarlisle62\_175375](#): > > My blower fan does not run on high, only 3 bars. The blower speed is determine by the automatic temperature control computer, if you lower the temperature setting or over ride the fan speed setting, does it increase? ---
**Author:** ![Pcarlisle62\_175375](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@Pcarlisle62\_175375](https://community.cartalk.com/u/Pcarlisle62_175375)\ **Post date:** [June 7, 2021, 1:23pm UTC](https://community.cartalk.com/t/blower-fan-runs-slow-stops/177275/7 "2021-06-07T13:23:38Z")
No, no effect by changing temperature. ---
**Author:** ![Scrapyard-John](https://avatars.discourse-cdn.com/v4/letter/s/f6c823/32.png) [@Scrapyard-John](https://community.cartalk.com/u/Scrapyard-John)\ **Post date:** [June 8, 2021, 12:03am UTC](https://community.cartalk.com/t/blower-fan-runs-slow-stops/177275/8 "2021-06-08T00:03:19Z")
Well, they’re usually somewhere above the passenger side footwell, up under the dash, encased in a plastic housing. BMW does things odd sometimes, though, so it may be in the trunk (kidding)! ---
**Author:** ![Pcarlisle62\_175375](https://avatars.discourse-cdn.com/v4/letter/p/3e96dc/32.png) [@Pcarlisle62\_175375](https://community.cartalk.com/u/Pcarlisle62_175375)\ **Post date:** [June 8, 2021, 12:28am UTC](https://community.cartalk.com/t/blower-fan-runs-slow-stops/177275/9 "2021-06-08T00:28:20Z")
Yeah, correct! Like the $800 battery! ---
**Author:** ![Darron](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/darron/32/21829_2.png) [@Darron](https://community.cartalk.com/u/Darron)\ **Post date:** [June 8, 2021, 5:54am UTC](https://community.cartalk.com/t/blower-fan-runs-slow-stops/177275/10 "2021-06-08T05:54:51Z")
It’s most likely the final stage resistor for the fan( white plastic part situated below the fan itself). if it’s an E90 there was a recall for wiring overheating in some markets.