Can a loose battery connection lead to alternator failure? - BMW M5 Forum and M6 Forums

Go Back   BMW M5 Forum and M6 Forums > BMW M5, M5 Touring, M6 and Z8 Forums > E39 M5 and E52 Z8 Discussion

E39 M5 and E52 Z8 Discussion 1998-2003 Advertiser's Forum


Reply
 
LinkBack Thread Tools Rate Thread Display Modes
Old 10th July 2007, 11:47   #1
scoopz
Moderator Emeritus
 
scoopz's Avatar
 
Join Date: Mar 2004
Location: Cheshire, UK
Age: 33

Garage: BMW M5 E60, Silverstone/Silverstone Full Perf

Sales Feedback: (0)

Blog Entries: 2
Thanks: 225
Thanked 251 Times in 103 Posts
Can a loose battery connection lead to alternator failure?

[admins - this relates to my father's E39 530i not an M5 so please move elsewhere if neccessary]

Summary of story below:
Question - If a battery terminal is loose can it cause an alternator to fail?

Full story:
My dad's car went into the bodyshop to have one side completely resprayed. When he got it back he noticed the clock in the car was not set right and assumed they disconnected the battery for some reason.

A few days later, after no more than 40 miles, he ended up with a warning light on the dash, a battery icon, followed immediately by trans fail warning (it's an auto) and he lost all power on a very dangerous and fast stretch of road that had no hard-shoulder. He waited for recovery, whilst waiting the battery was so low that the hazard warning lights wouldn't work after 5 minutes use and he couldn't gain access to the trunk to get the warning triangle


The RAC recovery arrived and towed him to a safe location then set about trying to jump start him. He then noticed that the positive terminal on the battery was completely loose. He tightened it completely before attempting to jump the car. He then diagnosed that the alternator wasn't charging the battery.

The vehicle was then recovered to the local dealer (same chain as bodyshop that didn't reconnect the battery properly).

Diagnosis from BMW - the alternator has failed and it needs a new one (600) and there's now way that could've been caused by a loose battery terminal according to them.

We asked for the exact problem with the alternator, they have just got back to me and said "something inside failed, we don't know what".

I did some quick Googling and found that a loose terminal could cause the alternator to run at 100% for a while or perhaps intermittent connection could make the alternator run on-off-on-off in rapid succession? If there is any evidence that a loose terminal could cause alternator failure please let me know so i can pass-the-buck when it comes to paying.
__________________
2005-12 E60 M5 :: Silverstone :: Silverstone Full Perforated
Delimited :: Twin rear screens + PS2 + DVD :: Origin B2+laser detect :: Pentagon Security Glass and most important of all a BMW Extended Warranty!
My Social Links :: @scoopz :: Blog :: YouTube :: G+
My Businesses :: Coopers Consulting Engineers :: iLogic Virtual Tours UK
scoopz is offline   Reply With Quote
Old 10th July 2007, 16:53   #2
verhagke
Member, P500 Sport, DSC On (>700)
 
verhagke's Avatar
 
Join Date: Jun 2005
Location: Connecticut

Garage: 2000 BMW M5 (Titanium Silver)

Sales Feedback: (0)

Thanks: 4
Thanked 20 Times in 15 Posts
Not sure, but I would think that if the alternator wasn't working when the car left the shop, the light would already have been on. At least a fair amount of time before the car stopped.
verhagke is offline   Reply With Quote
Old 10th July 2007, 17:19   #3
jclyman
M5 Expert (>4000)
 
jclyman's Avatar
 
Join Date: Jun 2003
Location: Rancho Palos Verdes, CA
Age: 76

Garage: 2003 M5 - Sterling Grey

Sales Feedback: (0)

Thanks: 2,374
Thanked 601 Times in 389 Posts
Quote:
Originally Posted by scoopz View Post
I did some quick Googling and found that a loose terminal could cause the alternator to run at 100% for a while or perhaps intermittent connection could make the alternator run on-off-on-off in rapid succession? If there is any evidence that a loose terminal could cause alternator failure please let me know so i can pass-the-buck when it comes to paying.
I have NEVER heard of that happening, BUT ... what Google said is correct as far as I know. Somewhere years ago, I read to never DISCONNECT the battery while the engine is running as it may "cook" the alternator circuitry, so it "could" happen on any car with an alternator ...

A body shop usually disconnects the battery while working on the cars (for safety reasons) ... but, normally they tighten the clamp when finished.

Since it isn't BMWs fault, you'll need to hit the body shop up for it though ...
__________________
"The greatest obstacle to discovery is not ignorance; it is the illusion of knowledge."

- Daniel Boorstin
jclyman is offline   Reply With Quote
Old 10th July 2007, 17:43   #4
ard
Super Moderator
 
ard's Avatar
 
Join Date: Apr 2003
Location: Sierra foothills, CA, USA

Garage: 2003 E39 M5, 2004 996TT X50 Modded...

Sales Feedback: (1)

Thanks: 1,224
Thanked 1,625 Times in 1,027 Posts
The intermittant connection can cause the internal voltage regulator to fail.

The shop is responsible for returning the car with a tightened battery connection.

Getting them to agree the alternator is their fault will be tough....
ard is offline   Reply With Quote
Old 10th July 2007, 17:59   #5
scoopz
Moderator Emeritus
 
scoopz's Avatar
 
Join Date: Mar 2004
Location: Cheshire, UK
Age: 33

Garage: BMW M5 E60, Silverstone/Silverstone Full Perf

Sales Feedback: (0)

Blog Entries: 2
Thanks: 225
Thanked 251 Times in 103 Posts
Thanks for the comments guys.

Quote:
Originally Posted by verhagke
if the alternator wasn't working when the car left the shop, the light would already have been on. At least a fair amount of time before the car stopped.
I agree, but I wander if the alternator was operating ok but somehow bumps in the road etc made the battery connection jump on and off and fry some circuit in the alternator? Guess I'll never know now. How far would an automatic car drive without an operational alternator if for some reason no warnings appeared?
Quote:
Originally Posted by jclyman View Post
Since it isn't BMWs fault, you'll need to hit the body shop up for it though ...
Sorry i may not have been clear on that, it WAS a BMW bodyshop at a BMW garage that did the respray and didn't reconnect the battery properly
Quote:
Originally Posted by ard
Getting them to agree the alternator is their fault will be tough...
I know, I thought as much. I was hoping there would be some well documented examples of situation similar to my own but guess not.
scoopz is offline   Reply With Quote
Old 10th July 2007, 18:04   #6
boostmiser
m5board.comoholic (>1000 posts)
 
boostmiser's Avatar
 
Join Date: Feb 2004
Location: DE

Garage: 2002 Alpine White M5

Sales Feedback: (0)

Thanks: 4
Thanked 40 Times in 19 Posts
Strange that the positive was loose. Generally you only need to remove the negative terminal.
I just got my car back from the body shop after two weeks. The battery was very weak and wouldn't hold a charge. I ended up buying a new one. Didn't think I had much lleverage for them to pick up the tab since it was 5 years old.
__________________
The Car: 2002 Alpine White ///M5 / Lemans Blue extended (sport) leather / aluminum trim
The Upgrades: Dinan Stg. 1 / Dinan RSB / TCD Sway Bar Brackets / UUC Evo III SSK / UUC DSSR / UUC Tranny mounts / MKIV Nav Unit / JL 500.1 Amp / JL 12w6v2 Sub
boostmiser is offline   Reply With Quote
Old 12th July 2007, 01:03   #7
M Cinco
Member, Sport: Off DSC: On (>50 posts)
 
M Cinco's Avatar
 
Join Date: Jun 2003
Location: Detroit/ Chicago
Age: 33

Garage: none

Sales Feedback: (0)

Thanks: 1
Thanked 0 Times in 0 Posts
Yes It can

__________________
"I'm serious, like when the M5 pedal is touching the floor"
M Cinco is offline   Reply With Quote
Old 12th July 2007, 11:34   #8
scoopz
Moderator Emeritus
 
scoopz's Avatar
 
Join Date: Mar 2004
Location: Cheshire, UK
Age: 33

Garage: BMW M5 E60, Silverstone/Silverstone Full Perf

Sales Feedback: (0)

Blog Entries: 2
Thanks: 225
Thanked 251 Times in 103 Posts
Thanks for the responses guys.
We've had the new alternator fitted now and just waiting to an independent report back on what caused it to fail. That way I'll hopefully know one one way or the other whether they were definitely to blame or not.
scoopz is offline   Reply With Quote
Reply

Bookmarks



Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes Rate This Thread
Rate This Thread:

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 On
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Trouble codes and descriptions LeMansBlau E39 M5 and E52 Z8 Discussion 1 19th April 2007 15:43
Battery tender question.... leebro1 E39 M5 and E52 Z8 Discussion 27 12th April 2007 21:08
Interstate MTP-93 Replacement Battery - check your installation greg E39 M5 and E52 Z8 Discussion 2 9th September 2006 00:10
Weak battery kalvin E39 M5 and E52 Z8 Discussion 43 15th December 2005 19:44
Stereo, Sub, Woofer, DSP, Pin, Bass, Speakers V-10 4 Me E39 M5 and E52 Z8 Discussion 0 26th September 2003 19:54

Loading...

All times are GMT +2. The time now is 14:02.



Everything Copyright 2000-2008. Do not use ANYTHING from this site without written permission. All images, graphics, sound files, video files and text appearing on this web site are the exclusive property of m5board.com and are protected under international copyright laws. All images, graphics, sound files, video files and text on this site are for on-screen and on-site viewing and listening only. No part of this web site may be reproduced, copied, saved, stored, manipulated, or used in any form for personal or commercial purposes without the prior written permission of m5board.com. Use of any image or graphic as the basis for another photographic concept or illustration is a violation of the copyright. Any copyright infringement will be prosecuted to the full extent of federal and international copyright laws. M5board.com is an enthusiast board and we don't condone any dangerous activity. Our airfield events are completely safe based on years of experience, we conduct them during clear visibility with mature participants that have several years of experience with high-performance automobiles, large unobstructed run-off zones on sealed off private former military airbases and we clearly mark the braking zones. If inexperienced with high speed driving we do not recommend organizing your own event but attending a high-performance driving school. The use of the term "BMW" on this site is for reference only, and does not imply any connection between m5board.com and BMW AG or BMW North America.