E46 Fanatics Forum banner

Parasitic current draw

68K views 116 replies 27 participants last post by  MrMCar 
#1 · (Edited)
hello, i have a 2001 330 xi, auto trans, 88 k, well maintained, driven in upstate NY winters. The battery/car has been discharging is it sits for a few days and the car is dead and won't turn over. I am not getting any OBDII codes, I have replaced the battery twice just to make sure. It is an AutoZzone duralast battery.

I am considering replacing the FSR (Final Stage Resistor), the FSR is associated with the A/C or Heater blower, I have not seen it act weird when in "auto" mode, but i'm watching it. I know that fuses #28 (5amp) and #50 (40 amp) are associated with the blower. Are these the correct ones to disconnect to troubleshoot the problem ?

I have a Fluke recording VOM , I put it inline with the positive battery terminal in the trunk. should I have used the negative ? The readings are as follows:

driver's door opened >2 amps
When driver's door is first closed, not asleep yet 200 ma
after 10 mins (sleep mode) min = 8 ma, max = 60 ma, avg = 16 ma.

I'm wondering how to get the blower to turn on (when the key is off and the car is in sleep mode after 16 mins) to test the FSR ? I ran my current draw test with the fuses plugged and unplugged and saw no difference. My next step is to replace the FSR (64-11-6-920-365) as it seems to fix most issues like this.

http://forum.e46fanatics.com/showthread.php?t=847871

The batteries are rated for 80 AH, that's amps times hrs. So if you are at the bmw spec. of 40 ma (milliamps) and 80 AH battery should take 83 days to discharge. To discharge in 5 days or so you would need an average drain of more like 600 ma.

So I'm puzzled, I checked battery terminals for corrosion, I looked at the engine compartment battery terms, they look good, I have no aftermarket stuff installed that could go bad. Would I be able to detect a current drain caused by corrosion using the inline amp meter method, It seems to me that it should. My guess is that corrosion on the + terminal is worse than on the -.

Can anyone help solve my issue. I tried to write this up in such a way that once we solve it, it will help others.

Thanks, DC
 
See less See more
#4 ·
^ What this guy said. In sleep mode you're under 50 mA of draw so you have no real parasitic current draw present. I'd look at charging voltage with that Fluke meter you have. Run the car with the meter at the battery (or underhood terminals) and view the charging voltage, should be low 14s or high 13s V. If it is, load up the alternator, turn on headlights, rear defrost... make sure it's doing it's job. If it's not charging then check fuse(s) in the charging circuit, wiggle wiring to it, check connections. Check to make sure you have battery voltage at B+ terminal of alternator.

Report back, and everyone stop slagging techs on this site or I'll stop helping.
 
#3 · (Edited)
Check ground connections, clean terminals under the hood, giggle and wiggle.

Sorry, I'm afraid you may have gone past some basics. You may not have, and if so, nevermind!

You need about 20 mins. on highway to charge a battery, and many short trips will kill it...especially in the cold.

Hunting a parasitic draw is a pain. I did it years ago. Turned out to be a bad battery. Even a new battery needs to be driven enough for what you're asking of it. Just saying.

Oops, OP, I skimmed reading just to say this, and then I saw that you 'looked' at terminal connections under hood.

Guys have had luck by removing the connections and looking underneath. Also there are a couple of monster groundstraps in the engine bay...also wherever the battery ground connects to.

Work the initial stuff thoroughly before jumping too far ahead. Alt connections? AM electronic device installed? All suspect.
 
#5 · (Edited)
The car is getting drained when not driving it. I have a brand new battery and I have charger it thouroughly using two different chargers. so I know that I have a good, fully charger battery, I wonder if I have to drive or start the car again and let it sit to get the FSR to act up again. Does the FSR start running on its own out of the blue or does it just not shut off when you've been driving it ? I have another car so I am letting the BMW sit. When I charge the battery, I do it right at the battery terminals with the rest of the car disconnected. I have a fully charged battery.

Dmax, if it's a grounding issue, wouldn't I see that with my recording amp meter ?

Next thing to try is measure battery voltages, connected, unconnected, key on but not started etc...Then check the alt voltage and report back.

The FSR is my number one suspect but I have not data to support this yet, I am not sure how the FSR fails which causes it to draw power when off ? Can anyone explain this. Also if you can post a picture of the FSR power connector location it will help people once we solve this riddle. The FSR connector has to be near the glove box as the FSR is up above and inside the glove box.

Thanks for all of your help, it's just a matter of time before this issue is solved, then on to my huge 100k style maintenance. I have been buying parts for the past two weeks, VANOS seals are my next buy. Not sure if i really need to do the thermostat, I bouight the metal vaned water pump. Does anyone have an opinion on the cooling system overflow tank, should I do it ?
 
#8 ·
OP boost (or charge battery) and start the car. While it's running check voltage at the battery OR just disconnect the -ve terminal while it's running... if the car dies then the alternator isn't charging. I have no idea why you're on this FSR kick and seem convinced it's at fault. Is there something you're not telling us and you messed around with the FSR/related circuitry in the past and are now having problems? Otherwise drop it as your "most likely suspect" unless you can show reason to believe it is. So far you haven't done that.

Here I go again doling out free advise which others will use to their benefit thus dropping my earnings more... it's the curse of being a considerate good person I guess... maybe I should stop posting on this site and become a leech on everyone elses intellectual property and only use it for my benefit. Damn those idiot techs.
 
#9 ·
Just like every other group of people, blacks, whites, techs, pygmies...they'll be good ones and bad ones.

The guys here heap on the bad techs--some think they're all bad and rip off artists, and evidently some are!

I have written often about finding a local indy that you can trust and work with. I can't move now because I've found mine!

You might not know this, but I've told my mechanic that if I ever become gay and he does too...well, nevermind! :lmao:

Cars are very complicated, and many here know that, and love their mechanics...and I agree, the good ones are good at many things!
 
#10 ·
#12 ·
Here is a screen shot of a resister I caught coming on all by itself. Aux a is tapped into the blower fuse. Notice the Amp draw and the battery voltage drop. This was back in 2007 when no one knew what was causing this. The dealer had installed a new resister already. The new resister was faulty we were able to catch and prove it.
 

Attachments

#13 · (Edited)
Hello everyone, thanks for all the help. I am charging the battery now, I will check the battery voltage and alternator charging condition.

What does the the "-ve terminal" connect to on the other end ? Does it go to the altenator ? I know that the pos. battery cable has 2-3 lines going to it. I never like to remove the battery from the alternator charging circuit. If the alternator runs without the battery load it can burn out.

I am interested in the FSR because I know this is a very common cause of parasitic draws and it seems to turn on by itself. I have not done anything to the car to make me think the FSR might be faulty. But as JB says the fsr can come on all by itself. I also don't have any aftermarket stuff like the infamous angel eyes, i checked for corrosion especially on the positive cable that goes to the engine compartment and found none.

here's my values

battery voltage after being charged for 10 hrs at 2 amps 12.4 vdc (charger not connected)
battery voltage while being charged at 2 amps 12.6 vdc (charger connected)
battery voltage while being charged at 6 amps 12.9 vdc (charger connected)
battery voltage while car is running 14.2 vdc

This tells me the alternator is OK, i know that the battery is good and can hold a charge. I'm kinda stumped, for the money I'm leaning towards just getting the FSR and trying it.
 
#14 ·
...
Can anyone help solve my issue. I tried to write this up in such a way that once we solve it, it will help others.

Thanks, DC
You wrote it in a way that confuses me.
Is your issue that the battery is discharging?
Why are you throwing in FSR in the picture? You said the AC isn't misbehaving. Are you suggesting that the FSR is sucking juice even when the car is completely off?
Then why are you measuring the door opener and not the FSR?

:confused:
 
#15 · (Edited)
here's what masterpro said in his post above and my reasponses in red:

"You wrote it in a way that confuses me.
Is your issue that the battery is discharging? Yes, my battery is discharging
Why are you throwing in FSR in the picture? You said the AC isn't misbehaving. Are you suggesting that the FSR is sucking juice even when the car is completely off? Yes FSR can suck juice when car completely off, see jbeurotechs post and plot, the FSR came on by itself and ran for 6-7 hrs
Then why are you measuring the door opener and not the FSR ? I'm not measuring the door opener, I had the drivers door opened and the lights came on,. so i documented my measured current draw before it went to sleep. I also measured the current draw with the blower fuses in and out and saw no change, I see no evidence that the FSR is bad but the FSR seems to be the most common fault. The FSR seems to be the most popular thing that can mysteriously turn on or stay on after the car is shut off. when i drive the car i will pay attention to the fan speed, I know it does change speeds by itself but this can be normal.

I seem to have a good alternator, good battery and less than 40 ma of current draw. maybe i'll just charge the battery completely and see how long it takes to discharge.
 
#16 ·
Hey Seth, in looking at your plot, after 6.5 hrs was the fan turning on or off. I'm not exactly sure what all the channels in plot mean but it appears like the fan was turning off after 6.5 hrs. so did thre fan come on by itself or did it stay running after the car was shut off ? i notice in the plot it says "AH" I assume this is amp-hrs, this drops steadily until; 6.5 hrs then flattens out like the fans shut off then. Can you explain it to us ?
 
#17 ·
Fan came on by its self. Ran for 6 hours then turned off. AH is the batteyr amp hours.

The tool used was a Midtronics DDR http://www.midtronics.com/shop/prod...ronics-idr-10-ingenr-diagnostic-data-recorder

Nice tool but its 5k price tag hurts!!

Tool was installed in clients car he left and took the car home. He drove by once a week and we downloaded the data card. We could move the aux lead to different circuits till we narrowed down the circuit with the draw. Then from the circuit we narrowed it down to fuses until we caught the draw. Mind you the trace you saw DID NOT lead to the car not starting it still started barley.

the client had had this issue for 1 year and no one not even the dealer was able to solve it.
 
#18 · (Edited)
Okay, I'm making a little progress, I started playing around with the climate control. i turned the car on and turned the fan to high, then to off. Even when the fan was off, i could hear a noise coming from the control box. In sleep mode, i'm drawing almost 1 amp. using my mechanics stethescope, i can hear what sounds like a motor running or a grinding noise coming from inside the a/c control box. When I pull fuses #28 (5amp) and #50 (40 amp) (associated with the blower), it makes no difference. It still is running and drawing current. I'm wondering if I need to wait longer than 10 mins for the car to go into full sleep mode. My money is still on the FSR, but it seems odd that the two fuses don't kill it. I guess I'll order an FSR and see if that works.
 
#19 ·
Okay, I'm making a little progress, I started playing around with the climate control. i turned the car on and turned the fan to high, then to off. Even when the fan was off, i could hear a noise coming from the control box. In sleep mode, i'm drawing almost 1 amp. using my mechanics stethescope, i can hear what sound like a motor running or a grinding noise coming from inside the a/c control box. When I pull fuses #28 (5amp) and #50 (40 amp) (associated with the blower), it makes no difference. It still is running and drawing current. I'm wondering if I need to wait longer than 10 mins for the car to go into full sleep mode. My money is still on the FSR, but it seems odd that the two fuses don't kill it. I guess I'll order an FSR and see if that works.
I think you need at least 20 mins. before all stuff turns off and car goes to sleep...I read that and now always suggest a 30 min. battery disconnect when trying to 'reset' something like maf. Don't know if that's needed all the time or not, but I've heard things stay on longer.
 
#21 ·
Let me jump onto this thread. Bought car Feb 2010 and haven't had any battery problems before. PO said he replaced battery in 2009. Recently I left my car parked for 4.5 weeks with the alarm activated. Came back last week, started it up for about 2 minutes, then used 12V air compressor to top off all 4 tires from the cigarette lighter. Then battery didn't have enough power to restart the car. I jumped the car and it's been fine since. Obviously I didn't run it long enough after that first start to recharge the battery, but I've inflated the tires from the car battery many times before without having a starting problem. Does this sound like normal battery performance?

--Does the car draw more power in sleep mode when the alarm is on?
--If battery is good, how long can the car sit and still start?
--Is there an easy way to check if the battery needs water, other than unbolting it and taking it out?
 
#24 · (Edited)
--Does the car draw more power in sleep mode when the alarm is on? Yes
--If battery is good, how long can the car sit and still start? the battery is 70-80 AH, so take how much it draws in sleep mode, say 40 ma divide that into 70 or 80. 70/.040 = 1750hrs or 73 days. You have to subtract off the extra current used everytime the doors are open, plus losses, my guess is that it should be able to sit for more than a month. I would use a battery tender whenever possible.


--Is there an easy way to check if the battery needs water, other than unbolting it and taking it out ? Its simple to unbolt it so that's the best way, you might be able to take the hold down off, disconnect the terminals, then check the level.

what kinda battery is in there ?
 
#23 · (Edited)
Thanks for the help guys, Does the FSR still draw current even with fuses 28 and 50 disconnected ? My guess is "yes", I also think that it must be more than a resistor, it is probably an electronic switch. Has anyone heard the sound that i'm hearing, it is loudest right behind the auto or fan switch of the control unit, it is making this noise even when the key is shut off. At this point, I don't have a better solution than to order the fsr, which i did from Autohauz for $61. As a side note, if yopu are reading this and thinking about ordering a a non-OEM, non "Behr" FSR, don't do it. I have read that the non OEM, Ebay style units fail very quickly. This is a high stress, high temperature part. I will feedback with the results of the FSR replacement and my current draw test after 16 minutes. i'm at the point now that the extra test time vs just replacing the FSR may not be warranted, intermittent issues are the toughest to nail down. Thanks Again ( Seth, Dmax, John, 2003_325i) , Don C. You guys really go out of your way to make this work and BMW owners and ethusiastists are really a special group. Seth, I want that Midtronics tool like yours for my Bday, i can dream, can't i ?
 
#25 · (Edited)
CelluloudHeros (Heroes?)... hope you don't mind my jumping into your thread. Wish I could help, but I haven't replaced my FSR yet, though I did replace the heater/AC blower fan because it was squeaking like a cricket. (Edit: specifically squeaking like a cricket on stimulants.) Thanks for the answers. I don't know what kind of battery is in there... a big heavy one! I have disconnected the negative terminal many times, so yeah when I get to it again I will disconnect battery, remove hold down, take it out and check the electrolyte level. I don't even know if it's a maintenance free battery or not.

2003_325i: Yes, that would have solved my problem! I just never had to run the engine while inflating the tires before. Of course I normally drive an hour on the freeway to get to any AutoX, so the battery is fully charged when I park it and start inflating the tires. Next AutoX I probably try to be mellow, leave my dedicated wheels and tires at home, and just run with my standard tires at whatever pressure they're at, instead of sweating the jack, torque wrench, and air compressor. I'm not good enough yet to be really competitive.
 
#26 · (Edited)
Okay, so i finally got around to changing the FSR module and it did not fix the problem. I am still drawing .62 amps after entering sleep mode. this problem is intermittent. I am going to attempt to pull all the fuses. Since this problem is intermittent, it is difficult to troubleshoot but it's drawing current now. drawing .62 amps all the time will draw down the battery in 3-5 days.

I could really use some help as to how to go about troubleshooting this issue. Also what is the best way to make sure the front terminals are clean. Am I right in thinking the positive front terminal is the one to clean ?

I am going to charge up the battery and start pulling fuses as Masterpo says. One things that I notice is that the A/C/Heater fan makes a growling/gurgling noise, after I turn the key off, i can still hear a noise from inside the a/c controller, this noise does eventually go away yet the current draw remains. The parasitic draw comes and goes and is hard to predict. The thing that's hard is that there are some modules controlled by multiple fuses, I also find it hard to remove/reinstall the fuses, what is the secret ? The little fuse puller tool only works fair for me.
 

Attachments

#28 ·
Okay, I pulled the first 41 fuses, #41 dropped the current draw 500 m-amps. # 41 (30 amp green) is related to Navigation, On-Board Monitor, Radio. I don't have a navigation system, just the old BMW business cassette, I am the original owner of the car and no one has taken the radio out etc... I have done all the work on the car myself so I know for the most part what has been done. Fuse #7 (5 amp yellow) is also related to Navigation, On-Board Monitor & Radio, but has no effect on the current draw when the car is in sleep mode. Can anyone explain What the on board monitor does and historic issues in this area ? I guess my radio could be the issue but It doesn't appear to be on when I'm drawing the extra 500 mamps.

thanks to all; that have rear and or helped with this issue. CH
 
#29 ·
So far two fuses drop the current while in sleep mode, #41 (radio, On-Board Monitor, Nav.) and # 63 (Air Conditioner). The growling noise stops when I pull fuse #63. I wonder if it's possible that the new Behr FSR/FSU (64 11 6 920 365) is defective and acts like the old one ? Anyway, I'm looking for a way to resolve this issue, I am going to charge the battery completely and take some current draw measurements and post them. Is there one thing that touches both of these areas, like a controller or something ? I am wondering of replacing the a/c heater controller would be expensive. Can anyone tell me how easy it is to remove the controller, i assume you remove the trim and unscrew it.
 

Attachments

#30 ·
Equipment Fuse No.
ABS, ASC 12, 33, 42, 53, 56
Adjustment Driver Seat 65
Adjustment Passenger Seat 70
Airbag 11
Air Conditioner 28, 62, 63
Automatic Gearbox Diesel 64
Blower 28, 50
Brake Light 9
Central Locking System 49, 52, 60
Central Locking System (Only Touring) 49, 52, 58, 60
Cigarette Lighter 47
Cigarette Lighter (Austrailia) 26, 47
DSC 12, 33, 40, 42, 53, 56, 61
DSC (4-Wheel Drive) 12, 33, 35, 40, 42, 53
Electric Fan 37
Electric Seat Heating 12, 42
Engine Control 27, 29, 30
Engine Control (Only M3) 22, 29, 30
Folding Outside Mirror 57
Front Fog Light 38
Fuel Pump 54
Garage Door Opener 26
Glove Box Light 52
Hand Lamp 52
Headlight Cleaning 51
Heated Outdoor Mirror, Passenger 25
Heated Rear Window 68
Heated Rear Window (Only Cabrio) 7, 68
Heated Spray Nozzles 25
Heater 23, 28, 62
Hinged Window (Only Coupe) 71
Horn 5, 55
Immobilizer 14, 67
Instrument Cluster 10, 34, 43
Inside Mirror Electrochromic 24, 67
Interior Light 49, 52
Light Module 9, 32
Make-Up Mirror Light 6
Manual Soft Top (Only Cabrio) 12, 42, 46
Navigation 7, 41
On-Board Computer 9
On-Board Diagnosis II 30, 43
On-Board Monitor 7, 41
Outside Mirror 31, 57
Parking Aid 24
Passenger Comp./ Trunk Lighting 52
Power Soft Top (Only Cabrio) 6, 12, 35, 42, 46
Radio 7, 41
Rain Sensor 15
Rear Wiper (Only Touring) 15, 45
Reversing Light 27
Roller Sun Blind 12, 42
Roll-Over Protective System (Only Cabrio) 13
Secondary Air Pump 36
Shifting Gate Illumination 40
Side Airbag 11
Sliding/ Tilt Roof 46
Socket 47
Speed Control 9
Sequential Transmission (Only M3) 8, 22
Starter Interlock 14
Telephone 7, 39
Thiefproofing System 49, 67
Trailer Coupling 44
Tyre Pressure 12, 31, 42, 69
Water Valve, A/C 62
Window Lift, Front 48, 49
Window Lift, Rear 71
Windscreen Washer System 49, 52, 59
 
#31 ·
I don't know the OE maker, but Behr makes lots of our parts and I'm pretty sure makes a good fsr, if not OE. Not promise, just a guess. It has a good reputation.

You asked about how a bad ground might cause I draw before and I don't know, but if you didn't clean under the terminals in the hood, now wouldn't hurt.

Could glovebox or trunk light be on? Did we cover that?

And then, we go back in the 'way back' machine...had you done any thing remotely in the area, or recall any weird incident you're sure is unrelated? I'm thinking you need to look for wire insulation damaged and touching metal (sort of thing)...major ground straps...just all to make electrical system happy.

You're convinced you have a parasitic draw and I can't argue with your multimeter numbers, because I haven't learned how to use one particularly well yet myself!

But, I might have mentioned that I chased a parasitic draw in my e36 for about 2 months before concluding it was the battery...and it was! If you haven't read up on bats yet, do. If you know tons...which is why you've told me to shut up about batteries four times now...bygones!

Too much, right? :lmao:
 
#32 ·
Hi Dmax, never too much, thanks, as always. I have already replaced the battery, which is why i don't think its that. Using a current meter is simple, just buy a decent one on eb ay, the fluke will last you forever or go to harbor freight, i can teach you how to use it. Just PM me. I have fuse 41 and 63 drawing current during sleep mode. With both of these pulled, I get 20 mamps of current drain (this is with the flashlight unplugged). The Glovebox light is not on as i have it unplugged, but it is a good point. I am very interested in the growling noise in the a/c control unit, I use a mechanics stethoscope, if i could only have one special tool, this would be it. I can hear the noise even without it, this noise goes away when #63 is pulled. I'm going to get some fresh current data,
 
#34 · (Edited)
I just mentioned to someone else with a 'blower sound' that I believe there's a fan behind the climate control for the cabin air temp sensor...it draws cabin air in through that tiny round louver. I wonder if that fan is the growl and your drain. I'm not sure of the name of that, or if it's independently replaceable, but I'll look real quick and see.

I also like the idea of leaving out the fuse that stops the draw...and checking that component's wires as best you can trace them. Mice eat wires; mechanics put them back where they rub and get cut...there are a million low odds things that can happen.

So, here's a sensor component...don't know more about it...maybe someone does. The AC control units are one part...no components available...other than this guy. Find its location, maybe you'll get lucky.

http://www.realoem.com/bmw/showparts.do?model=AM53&mospid=47723&btnr=64_0700&hg=64&fg=45
 
#33 ·
Will you stop blaming the FSR.
It's a resistor pack. It's a passive component. Just like a light bulb, it only draws current if the switch is on.
You already found the culprit fuse. Has nothing to do with FSR.
Leave it off for a few days and see if that stops draining your battery.
If it does, and you observe no ill effects, just leave it off.
 
#36 ·
41 is 'on board monitor' I have no idea what that does.

You know you have to wait 17 mins. after shutdown to pick up on parasitic draw, and even then, I know there is some expected draw when off...don't know what that is.

I also don't know what the size of your draw might be equivalent too. It sounds like we're talking a very small draw.

Since getting your new battery, how far have you driven?

Did you ever clean the terminals under the hood (under the terminals too) just coz I was so persistent about it? LOL

I'm not strong on electric stuff, OP, besides believing batterys are too often dismissed too early!

I can't read this all again, but did you check where the ground on the battery attaches to the car? That's about all I have...get good battery and make sure the grounds are good. Talk milliamps and I'm out of my field!

What are the driving habits of this car? A lot of short trips without a highway drive once a week could easily drain it...we get that a lot here. You need 20 mins. on the highway to charge it fully...and fyi, new batteries often aren't fully charged.
 
#37 ·
Masterpo, do a search on FSR/FSU, you will see that this is an extremely common failure part where it can stay on after the car is shut off, it is related to the heater/AC circuit. I can see that with fuse 41 ans 63 pulled, that the parasitic drain is gone, the question is are these two related and how do i fix them. The car does not have any modifications and no one else but me has worked on the car in years. Here's my measurement values:

battery voltage, car in sleep mode 12.4 volts

Fuse 41, 63 pulled, turn key to pos 2, turn fan on, turn key off after 5 mins the current draw is only .25 amps and then soon drops to .04 amps

Reinstall fuse 41,63 turn key to pos 2, turn fan on, turn key off, reading is 2.5 amps, open Glove box, =2.8 amps pull 63= 1.0 amps, pull 41= .4 amps, close Glove box = .1 amps

so fuse 63 is draining 1.8 amps and fuse 41 is draining .6 amps. these two seem to be related somehow. I'm hoping to tie these two together somehow.

Need to figure out how to pull the a/c control unit and radio.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top