Parasitic Battery Drain e53

[Crowz]

That's one of the reasons I went aftermarket for the sound system. When you turn the key off the radio turns off and it STAYS off.

[HotWheelsRedline]

Thanks -- I'll check out your thread about it.

[HotWheelsRedline]

Okay, I'm inclined to believe something like the MID is randomly kicking on (hence the random electronic sound in the dash when car is asleep) because with fuse 75 pulled, the car has been starting fine. No apparent battery drain over long non-run periods (up to 4-day sit times tested so far). Today, I put the multi-meter back on the battery, and with fuse 75 out, the reading dropped to .02 amps once the car went to sleep. With fuse 75 in, the lowest it dropped was .14 amps once asleep -- so that indicates a .12 amp draw.

Question is, if I purchase a pre-owned radio/receiver and swap it out, will it solve the problem? I'm finding them on eBay for about $180. The pixels on my display are shot, so that would also be an improvement.

Anyone care to weigh-in further w/words o' wisdom?

Thanks for playing along! This has been more of a PITA than I bargained for....

[wpoll]

The MID unit on the dash is just a display - no audio etc. inside it at all. You still need to isolate the fault to the actual radio (either inside the Business/Professional CD player or in the trunk - depends on your model) or the actual MID unit before replacing anything.

You might want to leave Fuse 75 in place and start unplugging the various modules listed here (while monitoring the sleep current): -

https://www.newtis.info/tisv2/a/en/e...5-fuse/hWIC4cC

Good Luck!

[HotWheelsRedline]

Originally Posted by wpoll

The MID unit on the dash is just a display - no audio etc. inside it at all. You still need to isolate the fault to the actual radio (either inside the Business/Professional CD player or in the trunk - depends on your model) or the actual MID unit before replacing anything.

You might want to leave Fuse 75 in place and start unplugging the various modules listed here (while monitoring the sleep current): -

https://www.newtis.info/tisv2/a/en/e...5-fuse/hWIC4cC

Good Luck!

Thank you for that. Trouble is, I don't know where to begin to start unplugging the various modules! Can you please point me in the right direction? Thanks.

[wpoll]

Originally Posted by HotWheelsRedline

Thank you for that. Trouble is, I don't know where to begin to start unplugging the various modules! Can you please point me in the right direction? Thanks.

Sure can try but let us know what exact stereo/Nav etc. config you have. You mentioned having a MID, so there is no Nav? CD player above the MID? Amps in trunk well on the left or next to the battery under the spare?

Once we know what you have, we can point you in the right direction.

[HotWheelsRedline]

Originally Posted by wpoll

Sure can try but let us know what exact stereo/Nav etc. config you have. You mentioned having a MID, so there is no Nav? CD player above the MID? Amps in trunk well on the left or next to the battery under the spare?

Once we know what you have, we can point you in the right direction.

Basic stereo that came with the car w/CD player above the radio/MID. No amps in trunk well on the left nor next to the battery. See attached photo.

[andrewwynn]

Wife's copy of x5 had parasitic drain turned out to be the FSU. Very easy to replace. Lucky for me I stumbled into that possibility early on into the diagnostics; the fan worked at all speeds so it didn't jump out as a gimme, but with 120k miles on the clock, i poked my head in and could tell from the design it was original (fat cone fins vs thin cylinders). replaced and all was well again. Not sure if the FSU is on that particular fuse; 7.5A is too little to run the blower, but if it's the control-side of the unit that could make sense.

Her car has the 'rest' mode that will allow the fan to run when the car is off (even without the key i think), so it would be an easy thing to have a defect and drain power.

[jdstrickland]

Originally Posted by HotWheelsRedline

Hey Guys - I'm new to this forum. Have been on BimmerForums since 2007 for my 1998 M3 e36 vert and my wife's 2005 X5 e53 SAV -- but learned this forum digs deeper into the X5. I've searched for parasitic battery drain threads and found lots of theories (FSU, NAV, TSU, Aux Fan, Radio, gear shift light/sleep mode, etc.)

Our X5 has a parasitic battery drain that started June 5th. Replaced the dead BMW battery (don't know if orig, we're 2nd owner) and alternator tested fine, so thought we were good to go. June 27th, car won't start again -- jumped, runs fine. July 8th, no start -- this time alternator showing drain. Replaced (115K-mile) alternator with new Bosch. July 19th, no battery power again. Thru all of this, never any warning lights on dash.

Re-charged the battery. With multi-meter bridging disconnected neg battery cable/terminal, and all power off, still reads a draw of .40 amps. Pulled/replaced all fuses in glove box and trunk while watching meter for any drop to normal, but nothing.

Now my friend/indy mechanic is checking it. Has ruled out the radio, Aux fan, TCU, FSU, NAV, sleep mode. Today says it may be the electronic trunk latch and is doing further testing. Fortunately, he's not charging me by the hour for diagnostic and gave me a free loaner 325ci.

Can anyone weigh-in with other theories/thoughts? Thanks much.

FOR THE RECORD
Sometimes they screw up the battery when they are making it. In my life, 65 years, I have managed to buy two or three batteries that were defective. The point here is to not point crooked fingers at the car until you know that the battery is not the problem.

[HotWheelsRedline]

Originally Posted by jdstrickland

FOR THE RECORD
Sometimes they screw up the battery when they are making it. In my life, 65 years, I have managed to buy two or three batteries that were defective. The point here is to not point crooked fingers at the car until you know that the battery is not the problem.

Good point. The two batteries put in since this all started are from AAA, and I've heard not-so-good stories about AAA batteries. I have an Interstate battery in my e36 M3 convertible (I think I recognize your username from that Bimmer forum), and have had good service from it. Perhaps I should swap-out for an Interstate and see what happens....