Parasitic battery drain.Solved

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SGP
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Post Sat Oct 01, 2016 2:25 pm

Hi , I have a 73 milliamp drain on the circuit fused by no 21.
I've checked all the interior lights including the glove-box and boot, they both switch off. The interior lights switch on and off with the door switches. The radio has been removed the wires are all clear. And the glove-box torch is not plugged in. (it's batteries are dead)
That only leaves the 13 button OBC. The only work done to the OBC recently was a replacement lightboard which is illuminating and dimming properly.
Is there a battery in the OBC that needs replacing?
Any one had the same experience?
Thanks in advance.
1989 320i
Last edited by SGP on Sat Oct 01, 2016 9:18 pm, edited 1 time in total.
If it ain't broke..
Fix it till it is :)
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ChrisHC
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Post Sat Oct 01, 2016 2:48 pm

Could it be the SI batteries?
SGP
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Post Sat Oct 01, 2016 7:10 pm

I've replaced the S.I. Batteries with brand new ones (lithium) That's working perfectly now it's on fuse 10.
TY.
If it ain't broke..
Fix it till it is :)
SGP
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Post Sat Oct 01, 2016 9:09 pm

Update, It turns out that the electric window isolator switch was causing the drain, it was very sticky from lack of use, so I opened it up and cleaned it with ptfe spray and now the drain has dropped to 14.2 milliamps! Result woohoo!
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Fix it till it is :)
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Brianmoooore
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Post Sat Oct 01, 2016 10:08 pm

You've got me on this one!
SGP wrote:That's working perfectly now it's on fuse 10..
Fuse 10 is only live when the ignition is switched on, so can't be implicated in any parasitic drain.
SGP wrote:Update, It turns out that the electric window isolator switch was causing the drain, it was very sticky from lack of use,
Similarly, the whole electric window circuit is also only live when the ignition is turned on, or when the front doors are open, so again can't have anything to do with parasitic drains.
SGP
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Post Sun Oct 02, 2016 3:04 pm

Hi Brian, thanks for picking this up, I forgot to mention that I noticed the hazard indicator button was sticky also. I pressed it on and off a several times after which it worked properly, maybe that could have been the culprit?
If it ain't broke..
Fix it till it is :)