I think I have parasitic drain!?!?!

[Bane]

Recently my 2001 3.0 X5 has been losing battery charge and I have had to jump it 3 or 4 times over the last month. 3 nights ago (during a rainstorm) it started up then the dash and all the electrical started flashing and barely working. I drove it a bit and it seem to charge back up and when I got it home it started the next morning and there was a long hum behind the climate control panel and then later it would not start. I started researching the forum and see that this common(ish) problem. I have had the X5 on a charger and it now starts back up and when I turn it off there was no hum. I see that the FSR is a many times the issue as well as I have had issues with the tailgate top not always opening when the back release is pushed.

My question is can I drive pull the FSR and drive around for a few days with out it to see if that is the problem?

[TerminatorX5]

Isn't Final Stage Resistor part of the AC system? I think you can tear the AC apart and still can drive (sans the leaks!!) Lets see what the other folks will say, but I'd say - yes, you can drive without the FSR

[jcp240z]

Could it be a bad battery?

[electricalserv x5]

Terminator is right ,it's part of the auxiliary fan for in the cabin.it is running all the time.........burning out your battery.

[Bane]

Thanks for the replies!!! Then could I also just unplug the top cap that the wires are attached to leaving the resistor where it is and get the same result?

[Qsilver7]

Yes. As mentioned, the FSR/FSU (final stage resistor or final stage unit) controls the HVAC system's blower...it helps regulate the variable speed etc. A failing/failed FSR/FSU will usually either run erratically (slowing down/speeding up)...or won't come on at all...or come on by itself (even when the engine has been shut down and key removed).

The latter is what can cause battery failure...if it is turning the HVAC blower on while you're parked over-night...the battery could be totally drained the next morning.

If this is NOT your issue...could you just have a bad battery? How old is your battery?

[Bane]

I put the car on the battery charger for approximately 12 hrs at the low 2 amp setting and it starts up and I just drove it 40 miles round trip and it drove normal. It also is shutting down quickly after the ignition is turned off with no long term humming behind the climate control. I unplugged the wire cap from the FSR and will see if that has any noticeable effect on the draw on the battery. I also tend to use the tailgate a lot and will stop that for now. I don't know how old the battery is as I purchased my X5 a year ago. As such I plan to have the battery tested...

[bcredliner]

I would eliminate a bad battery first by having it load tested at local auto parts store that will do for free. Battery is likely a replacement that should have a date of purchase on it.

[kevinflynn]

Had same symptom 2002 4.4i. even bought a new battery from BMW. Many jump starts and trickle charges. Turned out to be the FSR. The fan that ran down the battery is almost silent and it only ran after shutting off the car every once or twice a week. one night after car sitting 30 minutes I could hear a very slight sound i thought was under the hood. Took 10 minutes to swap out. You can reach up and remove it via feel. I was an idiot and convinced myself it wasn't the FSR. it was.
Good luck.
Kevin

[Bane]

Had the battery tested and it was bad...held no charge after several long trickle charges. With new battery the X5 seems like a whole different beast. I just realized there are lights under the outside door mirrors that come on at night...not sure if they did before. Since I have read so many posts that state new batteries running down after replacement due to parasitic draw I have a multimeter that I'm going to use to check the battery for any draw and have the alternator tested. Fingers crossed it was just the battery....