Troubleshooting broken heater fan? - The Unofficial BMW M5 Messageboard (m5board.com)

yep m5 · 8th March 2006, 05:38

yes it stopped working today so I went to the fuse box to see if it was the problem. I needed to look at fuse number 76 but I cant find it. It goes up to number 45 and that is it, unless its somewhere else. Any ideas anyone?

Black Beast · 8th March 2006, 07:15

If the blower is dead whether you are running the a.c. or heater, your final stage resistor is bad. Very common failure on e39's.
Mine died several months ago and I replaced myself in about 10 minutes following these directions: http://www.540i6.com/finalstagereplacement.html

The final stage resistor is about $80 from the dealer. You can find the same OEM part cheaper on eBay.

I would bet it is not a blown fuse, but a bad final stage resistor.

HTH.

jclyman · 8th March 2006, 08:06

Quote:

Originally Posted by Black Beast

If the blower is dead whether you are running the a.c. or heater, your final stage resistor is bad. Very common failure on e39's.

Very common failure on many BMWs ...

sjfamily · 8th March 2006, 08:44

I had the final stage resistor fail in my 2002 last year @ about 25k miles

yep m5 · 9th March 2006, 02:20

Quote:

Originally Posted by Black Beast

If the blower is dead whether you are running the a.c. or heater, your final stage resistor is bad. Very common failure on e39's.
Mine died several months ago and I replaced myself in about 10 minutes following these directions: http://www.540i6.com/finalstagereplacement.html

The final stage resistor is about $80 from the dealer. You can find the same OEM part cheaper on eBay.

I would bet it is not a blown fuse, but a bad final stage resistor.

HTH.

Thanks for that and will get straight onto it

Black Beast · 9th March 2006, 04:10

You're welcome. Another tell-tale sign that it is the FSR and not a fuse is if just prior to the blower not working at all, it was acting up, i.e. intermittently "stuck" on one speed, then working fine the next day. Mine did this a couple times before it went out completely. Heck, I couldn't even locate the fuse that was supposedly for the blower motor!

Being in So Cal in the middle of summer, I couldn't go without a.c. for long!

It is a bit of a PITA to locate, remove, and then replace the FSR, because it is located in such a crevice with other wires in the way and it is a tight fit for your hand/fingers...but it isn't something one can't do themself with a bit of persistence and patience....

Good luck!