Power drain from fuse 27 (or not) - Page 2

grounch · #11 04-17-2022, 05:37 PM

Will keep updated with amp readings.

Putting a switch would be an idea if the fuse wouldn't be controling essential things like cabin lights. Would imply switching them on manually when entering the car, just like home!
Does gm3 also controls interior lights and xenons? If not, means f27 is also connected to something else. That's why a full wiring diagram would be ideal. But no idea where to find it.

I'd say the battery goes at a nln starting point after couple of days. It's my daily so charged mostly every day.

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wpoll · #12 04-18-2022, 05:10 AM

Wiring diagrams are here: -

https://bmwteka.com/wds/ru/e53

(Use Chrome and it's auto-translate feature)

X5chemist · #13 04-18-2022, 09:26 AM

Detailed fuse circuit accessories can be found here: https://knigaproavto.ru/shemy/en/bmw...x-diagram.html

F27 is general power. Internal GMIII design powers a variety of components.

grounch · #14 04-18-2022, 10:01 AM

Thanks for the links I'll have a look.
Did a first amp test, putting the meter between battery neg and the neg cable. Hacked the door and trunk by pushing the locks as it was closed, lights turned off but somehow the car didn't went to sleep this way (P light stayed on after 16min).
I got around 700ma after lock, then dropped to 400 300 after few minutes. However removing the 27 fuse doesn't seem to reduce it, but turned off P light.
Had no time today to go through all the glovebox fuses, will try later. Trunk fuses removal did not make amps drop.

X5chemist · #15 04-18-2022, 10:20 AM

Check voltage drop at F11. The immobilizer system. Mine had 500 mA on it. F60 has 200 mA.

grounch · #16 04-20-2022, 08:31 AM

Little update about this mind fkin situation.

Had no time yet to check the fuses, just tried to unplug stuff and leave the voltmeter inside during the day.

So i unplugged the webasto (the 2 plugs on it) because i forgot to try it, and the voltage stopped dropping. Then plugged it back to confirm, there was no more drain...

Also now after driving, the battery is staying around 13v at sleep (drops to 12.7 12.8 when unlocking, then back to 13). Left it overnight, unlocked locked few times meanwhile, now i get 12.97v.

Is it normal to have such voltage or it's not supposed to reach 13v on a 12v battery? Engine on i get around 14.1v.

X5chemist · #17 04-20-2022, 11:45 AM

A battery at 12.6 is fully charged. A few can go higher. I've seen mine at 13.3 after a trickle charge. Up to 14.4 is acceptable. Anything out of those ranges is going to cause issues. Running should be 13.5-14.5.

The power cable does have more connections. I'm not familiar with those at the battery.

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