Mercedes SL Class Mercedes SL500 and Mercedes SL600 Roadsters.

Dead Battery Advice

Thread Tools
 
Search this Thread
 
Old Aug 15, 2005 | 04:03 PM
  #1  
sbeemish's Avatar
Thread Starter
|
Member
Joined: Nov 2003
Posts: 43
From:
Default Dead Battery Advice

94 SL500--If I do not drive the car for 4-5+ days the battery becomes too drawn down to start. I have replaced the battery and the charging system has been checked out --all are fine. My mechanic states no shorts or excess electrical draws exist. Does anyone have any suggestions?

As with my past posts, I receive excellent replies. Thank you all in advance.

Oh, I know it is a sin to not drive the car for that period of time but when I am with my family of 5, we do not seem to fit in the car....
 
Old Aug 16, 2005 | 12:47 AM
  #2  
sleepwalker's Avatar
Super Moderator
Joined: Apr 2004
Posts: 7,050
From: Philippine Islands
Default RE: Dead Battery Advice

how much electrical draw does the technician measure on your car? (in amperes).
 
Old Aug 16, 2005 | 01:09 AM
  #3  
Kajtek1's Avatar
Joined: Sep 2004
Posts: 771
From: Bay Area CA
Default RE: Dead Battery Advice

Our cars can sit for 5 weeks and will start with no problem, even with original 7-years old batteries.
One easy way to deal with your problem is to spend 7 buck on one of those
http://www.harborfreight.com/cpi/cta...emnumber=42292
 
Old Sep 6, 2005 | 10:15 PM
  #4  
sbeemish's Avatar
Thread Starter
|
Member
Joined: Nov 2003
Posts: 43
From:
Default RE: Dead Battery Advice

Mechanic says pulling 400+ma
He says that is too high. Suggests that the radio, top, seats or alarm may be the culprit and suggests we begin looking there. Any suggestions from the forum? I know the computer etc pulls some draw but not that much.
My first guess is the radio...I had same replaced a little while ago due to some other problem and that may be a weak spot.
Suggestions?

 
Old Sep 6, 2005 | 10:32 PM
  #5  
Kajtek1's Avatar
Joined: Sep 2004
Posts: 771
From: Bay Area CA
Default RE: Dead Battery Advice

Did your mechanic pulled the fuses out at measured the draw on each circuit?
That takes about 2 minutes and will answer your question. Or at least narrow it down.
 
Old Sep 6, 2005 | 11:01 PM
  #6  
sleepwalker's Avatar
Super Moderator
Joined: Apr 2004
Posts: 7,050
From: Philippine Islands
Default RE: Dead Battery Advice

400+ma
too high. 100 milliamperes is at least acceptable.

try removing the fuse of every components one by one till the current go down and you will find out the source.

keep the ammeter in series connection with the battery while doing it and observe.
 
Old Sep 7, 2005 | 02:52 AM
  #7  
sbeemish's Avatar
Thread Starter
|
Member
Joined: Nov 2003
Posts: 43
From:
Default RE: Dead Battery Advice

I shall communicate your suggestions to the mechanic and see what is uncovered. Thank you. I shall report back.
 
Old Sep 11, 2005 | 12:00 AM
  #8  
sbeemish's Avatar
Thread Starter
|
Member
Joined: Nov 2003
Posts: 43
From:
Default RE: Dead Battery Advice

I am pulling between 270 to 400 ma when the car and alarm are off. The lower number is after the car sits for several minutes. I am told that is normal (to reduce). 270 is still high. Each and every fuse have been pulled and the figure does not really change. I have had the entire audio system checked and that is fine. The mechanic believes that some component is tapped directly into the wiring and pulling the juice. His next step is checking the wiring deeper. Any other suggestions.
 
Old Sep 13, 2005 | 09:24 PM
  #9  
sbeemish's Avatar
Thread Starter
|
Member
Joined: Nov 2003
Posts: 43
From:
Default RE: Dead Battery Advice

Problem found after going through the fuses three times. The last method was the best. Pull EVERY fuse out and replace one (only) at a time. The draw was from the fuse that powered the cluster....The cluster is the key problem. Any suggestions? The cluster replacement is a staggering cost.....help quick please
 
Old Sep 17, 2005 | 12:48 AM
  #10  
sbeemish's Avatar
Thread Starter
|
Member
Joined: Nov 2003
Posts: 43
From:
Default RE: Dead Battery Advice

Found someone to work on the cluster. Short in the cluster was the problem. The repair was far less than the replacement. Thanks to those who responded with suggestions. sb
 



All times are GMT -5. The time now is 05:17 PM.