Can a loose battery connection lead to alternator failure? - BMW M5 Forum and M6 Forums
E39 M5 and E52 Z8 Discussion 1998-2003 Advertiser's Forum

 
LinkBack Thread Tools Rate Thread Display Modes
post #1 of 8 Old 10th July 2007, 11:47 AM Thread Starter
scoopz
Moderator Emeritus
 
scoopz's Avatar
 
Join Date: Mar 2004
Location: Cheshire, UK
Age: 34
Posts: 916
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 :: C Inside Media - Google Street View Team
scoopz is offline  
Sponsored Links
Advertisement
 
post #2 of 8 Old 10th July 2007, 04:53 PM
verhagke
Member, P500 Sport, DSC On (>700)
 
verhagke's Avatar
 
Join Date: Jun 2005
Location: North Carolina
Posts: 714
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  
post #3 of 8 Old 10th July 2007, 05:19 PM
jclyman
M5 Expert (>4000)
 
jclyman's Avatar
 
Join Date: Jun 2003
Location: Rancho Palos Verdes, CA
Age: 77
Posts: 4,624
Thanks: 2,374
Thanked 602 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  
post #4 of 8 Old 10th July 2007, 05:43 PM
ard
Super Moderator
 
ard's Avatar
 
Join Date: Apr 2003
Location: Sierra foothills, CA, USA
Posts: 12,137
Thanks: 1,328
Thanked 1,714 Times in 1,096 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  
post #5 of 8 Old 10th July 2007, 05:59 PM Thread Starter
scoopz
Moderator Emeritus
 
scoopz's Avatar
 
Join Date: Mar 2004
Location: Cheshire, UK
Age: 34
Posts: 916
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.

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 :: C Inside Media - Google Street View Team
scoopz is offline  
post #6 of 8 Old 10th July 2007, 06:04 PM
boostmiser
m5board.comoholic (>1000 posts)
 
boostmiser's Avatar
 
Join Date: Feb 2004
Location: DE
Posts: 1,463
Thanks: 4
Thanked 43 Times in 21 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  
post #7 of 8 Old 12th July 2007, 01:03 AM
M Cinco
Member, Sport: Off DSC: On (>50 posts)
 
M Cinco's Avatar
 
Join Date: Jun 2003
Location: Detroit/ Chicago
Age: 34
Posts: 95
Thanks: 1
Thanked 0 Times in 0 Posts
M Cinco is offline  
post #8 of 8 Old 12th July 2007, 11:34 AM Thread Starter
scoopz
Moderator Emeritus
 
scoopz's Avatar
 
Join Date: Mar 2004
Location: Cheshire, UK
Age: 34
Posts: 916
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.

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 :: C Inside Media - Google Street View Team
scoopz is offline  
Reply

Bookmarks

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the BMW M5 Forum and M6 Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in









Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.




Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes Rate This Thread
Linear Mode Linear Mode
Rate This Thread:



Similar Threads
Thread Thread Starter Forum Replies Last Post
Trouble codes and descriptions LeMansBlau E39 M5 and E52 Z8 Discussion 1 19th April 2007 03:43 PM
Battery tender question.... leebro1 E39 M5 and E52 Z8 Discussion 27 12th April 2007 09:08 PM
Interstate MTP-93 Replacement Battery - check your installation greg E39 M5 and E52 Z8 Discussion 2 9th September 2006 12:10 AM
Weak battery kalvin E39 M5 and E52 Z8 Discussion 43 15th December 2005 07:44 PM
Stereo, Sub, Woofer, DSP, Pin, Bass, Speakers V-10 4 Me E39 M5 and E52 Z8 Discussion 0 26th September 2003 07:54 PM

Posting Rules  
You may post new threads
You may 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

 
For the best viewing experience please update your browser to Google Chrome