Bad blower resistor cause dead battery?

v8z4 · 05-28-2013, 04:00 PM

Having an issue with my 03 Z4. If it sits for 3-5 days, the battery has drained down and its hard to start.

I just had the same issue (only much worse) in my wifes 03 325i and all signs pointed to a bad FSR (blower final stage regulator). In my wife's car, there was a noticeable surging in the air flow and eventually the fan would not run "high speed" at all. The day after the fan stopped being able to run "high", the car would not crank (battery was dead). Charged the battery and it was again dead the following day. I ran a search online and found the the FSRs die in the E46s, thereby causing the electronics to stay "awake" and drain the battery.

So I'm wondering if I could have a bad FSR in my Z4. Has anyone run into an issue with their Z4's FSR dying?

Chris

pokeybritches · 05-28-2013, 08:10 PM

Would it be possible to test the resistance of the FSR? I'm not familiar with them.

v8z4 · 05-28-2013, 08:38 PM

Quote:

Originally Posted by pokeybritches

Would it be possible to test the resistance of the FSR? I'm not familiar with them.

Not that I know. I think it's more of a solid state regulator rather than a 'resistor' but I have no real clue what's in it.

norcal_cyclist · 05-28-2013, 09:54 PM

Perform a standard draw test with it installed then removed

v8z4 · 05-28-2013, 10:21 PM

I have no idea where it is located in the Z4.

v8z4 · 05-28-2013, 11:32 PM

Well, I ran a draw test and there is only 0.01 to 0.02 amps being pulled. So I guess it's just something I have to live with (I have a small motorcycle battery). Oh well, thanks everyone.

nate96 · 05-29-2013, 05:06 PM

Quote:

Originally Posted by v8z4

I have no idea where it is located in the Z4.

The FSR is a PITA to get at in our cars. You need to remove the glove compartment and the passenger air bag. You may not need to remove the passnger airbag if you can fit under there with just the glovebox removed. Then you need to fiddle with the FSR as it is behind the ducts. Off of the FSR to the blower motor you can unplug the wires. Take a voltage tester and see what kind of voltage you are getting out of it when you turn the fan on. I looked into this as the bearing in the blower motor is a little dry and I can hear it running. There is a bar in front of the blower motor that I guess you need to remove the radio and there is a release for it. I have not made another attempt to look at it again. I looked into this as I just replaced a FSR in a friends 325 and it took 5 mins. So I was hoping ours would be the same.

elerner61 · 05-29-2013, 10:19 PM

Yes, replacing the FSR in our cars is sadly a 2+ hour ordeal. Mine blew in the middle of winter (of course) and I had to have the shop replace it for me (too cold in the garage....brrrrr). At least they cut me a good price on the part.

v8z4 · 05-29-2013, 11:23 PM

Wow, I hope mine never dies! My wife's 325i was a 30min job and most of that is because I was taking my time.

05-28-2013, 04:00 PM	#1
v8z4 Private First Class 16 Rep 148 Posts Drives: 2003 Z4 roadster Join Date: Sep 2012 Location: Fountain Hills, AZ iTrader: (1)	Bad blower resistor cause dead battery? Having an issue with my 03 Z4. If it sits for 3-5 days, the battery has drained down and its hard to start. I just had the same issue (only much worse) in my wifes 03 325i and all signs pointed to a bad FSR (blower final stage regulator). In my wife's car, there was a noticeable surging in the air flow and eventually the fan would not run "high speed" at all. The day after the fan stopped being able to run "high", the car would not crank (battery was dead). Charged the battery and it was again dead the following day. I ran a search online and found the the FSRs die in the E46s, thereby causing the electronics to stay "awake" and drain the battery. So I'm wondering if I could have a bad FSR in my Z4. Has anyone run into an issue with their Z4's FSR dying? Chris __________________ Chris
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05-28-2013, 08:10 PM	#2
pokeybritches Colonel 479 Rep 2,782 Posts Drives: ESS/G-Power Z4M, VF Z4, 996tt Join Date: Sep 2009 Location: Los Angeles iTrader: (12) Garage List 2006 BMW Z4M [10.00] 2006 BMW Z4M [8.50] 2003 BMW Z4 3.0i [9.00]	Would it be possible to test the resistance of the FSR? I'm not familiar with them. __________________ VF Engineering Z4 3.0i, ESS Z4M, G-Power Z4M, 996 Turbo
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05-28-2013, 09:54 PM	#4
norcal_cyclist Private First Class 4 Rep 100 Posts Drives: 2006 Z4 3.0si Join Date: Nov 2009 Location: Rancho Cordova iTrader: (0) Garage List 1999 BMW 323i [0.00]	Perform a standard draw test with it installed then removed __________________
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05-28-2013, 10:21 PM	#5
v8z4 Private First Class 16 Rep 148 Posts Drives: 2003 Z4 roadster Join Date: Sep 2012 Location: Fountain Hills, AZ iTrader: (1)	I have no idea where it is located in the Z4. __________________ Chris
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05-28-2013, 11:32 PM	#6
v8z4 Private First Class 16 Rep 148 Posts Drives: 2003 Z4 roadster Join Date: Sep 2012 Location: Fountain Hills, AZ iTrader: (1)	Well, I ran a draw test and there is only 0.01 to 0.02 amps being pulled. So I guess it's just something I have to live with (I have a small motorcycle battery). Oh well, thanks everyone. __________________ Chris
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05-29-2013, 10:19 PM	#8
elerner61 Major 157 Rep 1,107 Posts Drives: '07 Z4M Roadster Join Date: May 2011 Location: Mount Kisco, NY iTrader: (0)	Yes, replacing the FSR in our cars is sadly a 2+ hour ordeal. Mine blew in the middle of winter (of course) and I had to have the shop replace it for me (too cold in the garage....brrrrr). At least they cut me a good price on the part.
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05-29-2013, 11:23 PM	#9
v8z4 Private First Class 16 Rep 148 Posts Drives: 2003 Z4 roadster Join Date: Sep 2012 Location: Fountain Hills, AZ iTrader: (1)	Wow, I hope mine never dies! My wife's 325i was a 30min job and most of that is because I was taking my time. __________________ Chris
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