BMW M3 Forum (E90 E92)

BMW Garage BMW Meets Register Search Today's Posts Mark Forums Read


Go Back   M3Post - BMW M3 Forum > E90/E92 M3 Technical Topics > Coding / ConnectedDrive / Audio-Video / Electronics / Bluetooth / I-Drive & Nav
 
Post Reply
 
Thread Tools Search this Thread
      10-28-2009, 07:11 PM   #1
elp_jc
Brigadier General
 
Drives: .
Join Date: May 2008
Location: .

Posts: 4,910
iTrader: (0)

Electrical question about front roof console

Hi gang. Want to hardwire my V1 from the console, but have 2 questions. Does BMW use a positive or negative 'ground'? And if I 'wake up' my car with the console disconnected, would my car throw any codes? I always leave my doors partially locked (first click only) so all the electronic crap doesn't run and drain the battery when I open the doors to work in my car. Thanks gang.

Last edited by elp_jc; 11-02-2009 at 01:12 AM.
elp_jc is offline   United_States
0
Reply With Quote
      10-28-2009, 08:14 PM   #2
TLud
Colonel
 
TLud's Avatar
 
Drives: '12 Golf R
Join Date: Jun 2008
Location: Texas

Posts: 2,280
iTrader: (3)

1. It's a negative ground.

2. I wouldn't think that powering up with the console disconnected would throw any codes, but the BMW Assist/SOS is up there, so that _may_ trigger an error.

3. You can always try, but I don't think those two front clips would make for a good ground. I haven't played around up there (yes, I went down the A-pillar to the fuse box). Is there a frame bolt of some kind up there?

Watcha installing?
__________________
'09 Interlagos Blue E92 M3 (sold to a good home)
TLud is offline   United_States
0
Reply With Quote
      10-28-2009, 08:42 PM   #3
J08M3
Major General
 
J08M3's Avatar
 
Drives: 2011 M3 COUPE
Join Date: May 2008
Location: NEW YORK

Posts: 6,012
iTrader: (8)

just do as the instructions in this thread
http://www.e90post.com/forums/showthread.php?t=97545

I've had mine hardwired for almost 1.5 years like this with no issues at all
__________________
J08M3 is offline   United_States
0
Reply With Quote
      10-28-2009, 09:13 PM   #4
GregW / Oregon
Commander-In-Chief
 
Drives: 2015 M4 Coupe, 2012 ML350
Join Date: Nov 2005
Location: Lake Oswego, OR

Posts: 7,536
iTrader: (1)

Garage List
V1 hardwire

Quote:
Originally Posted by J08M3 View Post
just do as the instructions in this thread
http://www.e90post.com/forums/showthread.php?t=97545

I've had mine hardwired for almost 1.5 years like this with no issues at all
Good DIY. Only improvement I would make is install a phone jack coupler in the console face so you can directly plug in a short (12") cable rather than having it hanging down all the time. This is how I did my E46. I've got the parts for this car, just need to get around to it.
Attached Images
 
__________________

Greg Lake Oswego, Oregon, USA
2015 M4 Coupe - Silverstone/Sakhir/CF
2012 ML350
GregW / Oregon is offline   United_States
0
Reply With Quote
      10-28-2009, 09:56 PM   #5
elp_jc
Brigadier General
 
Drives: .
Join Date: May 2008
Location: .

Posts: 4,910
iTrader: (0)

Quote:
Originally Posted by TLud View Post
1. It's a negative ground.
Watcha installing?
Didn't ask my question correctly. I meant to ask if switches handle juice or ground, and just like I suspected, it's juice, opposite the rest of the world. So the common circuit I pointed on my pic is just ground. Can't use my method then. Will use the linked one.

As for your question, you missed my first sentence. Just hardwiring my V1 buddy. Everything is so tight on the A pillars, prefer doing it this way. I'll use regular phone line cut to size (probably a foot), and insulate things in there to prevent rattles. Take care.

EDIT: A super easy way to remove the roof console (courtesy of another member but don't remember who): Remove the clips that secure the sun visors (next to the rearview mirror) and headliner drops an inch. Enough for even fat fingers to easily reach the clips from either front seat. Hope this helps.

Last edited by elp_jc; 10-28-2009 at 10:18 PM.
elp_jc is offline   United_States
0
Reply With Quote
      10-28-2009, 10:17 PM   #6
elp_jc
Brigadier General
 
Drives: .
Join Date: May 2008
Location: .

Posts: 4,910
iTrader: (0)

Quote:
Originally Posted by GregW / Oregon View Post
Only improvement I would make is install a phone jack coupler in the console face so you can directly plug in a short (12") cable rather than having it hanging down all the time.
Hey Greg, that's a good idea, but still defeats the purpose of hardwiring if you use the detector on the windshield (like me), but works great on your chosen location. I don't like that the console looks butchered, but it's a minor detail. By the way, what's that microphone location for? I have nav, sos, and bluetooth, and it's not used.

As a comment, I always tuck the hardwired jack back into the headliner when not used (leaving an invisible loop to pull it out when needed), but need to make sure the headliner is not too tight to prevent that on this car. Only then I'd consider your option, but securing the wire behind the mirror is a more likely one. Thanks for posting buddy.
elp_jc is offline   United_States
0
Reply With Quote
      10-29-2009, 07:25 PM   #7
elp_jc
Brigadier General
 
Drives: .
Join Date: May 2008
Location: .

Posts: 4,910
iTrader: (0)

Ended up hardwiring it like Jo8M3 did, but with a regular telephone wire (used the T20 torx screw on the roof for ground, with the appropriate terminal). To quiet the rattles/squeaks, installed foam all around, and put tape all around the metal opening where the console mounts. To tuck the cable out of sight when not in use, installed a piece of velcro (with a screw) on the headliner where it almost touches the windshield, right where the matching piece on the telephone jack (attached with 2 zip ties) reaches when not in use. The cable exits the headliner right by the mirror. Everything is black, so you can't see anything even when looking up outside the windshield.

Had to insert another piece of wire since detector wasn't working when I was about to lock the console in place. Wasn't real happy about not having a solid connection, but hopefully the V1 doesn't draw enough juice to be a problem. I'll try it on a 1K-mile trip at the end of the month (crossing fingers). Thanks to all who contributed .

Last edited by elp_jc; 11-02-2009 at 01:05 AM.
elp_jc is offline   United_States
0
Reply With Quote
      11-08-2009, 12:44 AM   #8
elp_jc
Brigadier General
 
Drives: .
Join Date: May 2008
Location: .

Posts: 4,910
iTrader: (0)

Quote:
Originally Posted by J08M3 View Post
I've had mine hardwired for almost 1.5 years like this with no issues at all
Was testing my V1 today, and found a 'problem': it does not work with the moonroof open . It has to be fully closed. I grounded it with the torx screw, not the hex one more to the left; don't know if that has anything to do with that, but was scratching my head trying to figure out what's happening (curiosity more than anything else ).

Anyway, not a big deal to me since I never actually use the detector with the moonroof open (was just testing it), but just a heads up in case it is to you.
elp_jc is offline   United_States
0
Reply With Quote
Post Reply

Bookmarks

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -5. The time now is 01:16 AM.




m3post
Powered by vBulletin® Version 3.7.0
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST