Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help




Go Back   PeachParts Mercedes-Benz Forum > Mercedes-Benz Tech Information and Support > Mercedes-Benz SL Discussion Forum

Reply
 
LinkBack Thread Tools Display Modes
  #1  
Old 01-29-2010, 11:38 AM
Registered User
 
Join Date: Dec 2003
Location: TN
Posts: 101
Battery drain on 380SL

Hello again.
Been fighting a slow battery drain for a few years now. Since I seldom drive the car, I simply disconnect the battery after each time I drive.
With Spring approaching, I've finally decided to find the drain and fix it (if possible).

Any ideas as to how/where to start? NOTE: My suspicions point to the Becker radio/cassette player (as I've checked trunk light, glove box light, etc). I'm electrically-challenged, so details appreciated.

As always, thanks.


Ragtopper
1982 380SL
Reply With Quote
  #2  
Old 01-30-2010, 11:24 AM
meltedpanda's Avatar
Certified Benzaholic
 
Join Date: Mar 2003
Location: Central Ky
Posts: 6,130
how long between starts does it drain? How "new" is the battery. Things that run with the key off in your car are limited - clock is about it. You may be shorting to ground somewhere , I would start with the battery connections themselves , looking closely for corosion on the ground side. Could be anly switch ( interior lights) that is stuck "on" may need to do some tracing.
Also possible your ignition switch may have issues , but less likely
__________________
Ron
2011 Porsche Cayman - Bond,James Bond
99 E320 THE Queen Mary
62 220b - Dolly - Finally my Finny!
72 450SL, Pearl-SOLD
16 F350 6.7 Diesel -THOR
07 Lexus RX 350 - Lexi
14 38HP John Deere 3038E Tractor -Mean Green
84 300SD, Benjamin -SOLD
71 220 - W115-Libby ( my first love) -SOLD
73 280 - W114 "Organspende" Rest in Peace
81 380 SL - Rest in Peace
Reply With Quote
  #3  
Old 01-30-2010, 01:34 PM
Registered User
 
Join Date: Oct 2008
Location: Phoenix, AZ
Posts: 349
Often batteries that are not "exercised" (used) periodically will go flat by themselves.
There have been reports of the Becker radio causing a drain.

I am going to have to complete that Automotive Electrical Troubleshooting 101 article that's been kicking around in my head for a while.

Some people get one of those book sized solar panel battery chargers around here to keep up the batteries in their RV's. I think I saw one for $19.95 somewhere a while ago.
__________________
Remember, it's not just a car. It's an Adventure.
Reply With Quote
  #4  
Old 01-30-2010, 02:33 PM
meltedpanda's Avatar
Certified Benzaholic
 
Join Date: Mar 2003
Location: Central Ky
Posts: 6,130
pull the fuse to the becker and see if it helps, Radio is right , some tales of beckers causing a drain, I had forgotten about that
__________________
Ron
2011 Porsche Cayman - Bond,James Bond
99 E320 THE Queen Mary
62 220b - Dolly - Finally my Finny!
72 450SL, Pearl-SOLD
16 F350 6.7 Diesel -THOR
07 Lexus RX 350 - Lexi
14 38HP John Deere 3038E Tractor -Mean Green
84 300SD, Benjamin -SOLD
71 220 - W115-Libby ( my first love) -SOLD
73 280 - W114 "Organspende" Rest in Peace
81 380 SL - Rest in Peace
Reply With Quote
  #5  
Old 01-31-2010, 02:20 AM
coleyjf's Avatar
Old dog - new tricks
 
Join Date: May 2005
Location: East Midlands of the UK
Posts: 264
Tracker?

Hi Ragtopper

Could there be a "Tracker" lurking somewhere? - Only ask because that was the cause of some of my battery drain. They can be fitted in the most obscure places. I never actually found mine but found the connection to it in the end so i could disconnect it ( the contract had long expired) !

Also is there an after market alarm fitted? Mine drains the battery in about 2 -3 weeks.

Cheers

Jim
__________________
Keep your Motor runnin'

Jim's '88 300SL
Reply With Quote
  #6  
Old 01-31-2010, 01:05 PM
Registered User
 
Join Date: Dec 2003
Location: TN
Posts: 101
By "tracker", do you mean a surveillance device? If so, doubtlful as my whereabouts are usually confined to my desk or my recliner. .
And no aftermkt alarm. Originally, there was an old cell phone installed in car, but I removed it upon purchase.
Ron: are you referring to fuse inside Becker unit? Or, fuse in kick panel fusebox?

I'll search for info on Becker drain.
RadioTek - will eagerly await your article.

Thanks.

Ragtopper
1982 380SL
Reply With Quote
  #7  
Old 01-31-2010, 01:13 PM
Registered User
 
Join Date: Dec 2003
Location: TN
Posts: 101
Also:

I should also note that the radio will function without the key in the ignition (but I do not leave radio on). I suppose this means that it's directly wired?

Could this be the culprit?

Ragtopper
1982 380SL
Reply With Quote
  #8  
Old 01-31-2010, 04:21 PM
Registered User
 
Join Date: Jul 2009
Location: Stouffville ON, Canada
Posts: 13
That radio is the most likely culprit. With ignition off, it should be only connected to the battery to preserve the preset station memory. This is usually the red wire. The yellow wire is live when ACC or ignition is on. I suspect in your case both wires are connected together to the live battery wire.
Reply With Quote
  #9  
Old 01-31-2010, 08:03 PM
meltedpanda's Avatar
Certified Benzaholic
 
Join Date: Mar 2003
Location: Central Ky
Posts: 6,130
I am thinking fuse box , just to see if it helps, I guess you could pull the fuse on the radio , but if it is a short to it, may still drain
__________________
Ron
2011 Porsche Cayman - Bond,James Bond
99 E320 THE Queen Mary
62 220b - Dolly - Finally my Finny!
72 450SL, Pearl-SOLD
16 F350 6.7 Diesel -THOR
07 Lexus RX 350 - Lexi
14 38HP John Deere 3038E Tractor -Mean Green
84 300SD, Benjamin -SOLD
71 220 - W115-Libby ( my first love) -SOLD
73 280 - W114 "Organspende" Rest in Peace
81 380 SL - Rest in Peace
Reply With Quote
  #10  
Old 02-04-2010, 06:24 PM
Registered User
 
Join Date: Mar 2007
Location: Pine Bluff, Ar.
Posts: 28
Just go a new 560 and had a drain too. I found the antenna was not shutting off. It didn't keep running, just stopped and the motor would stay warm. I could hear a small click when the battery was connected / disconnected. I haven't fix it yet, I just unplugged it at the antenna and no more drain. If this is it, you could feel the motor after the car is shut off for a while and with a good battery, it will feel warm. Dash switch didn't make any difference.
Reply With Quote
  #11  
Old 02-11-2010, 03:59 PM
Registered User
 
Join Date: Apr 2007
Location: Sierras, CA
Posts: 137
While I don’t profess to be an expert in automotive electrical issues, I just recently had to deal with a similar issue on one of my larger CASE Loaders that was 'draining' while parked. The first thing I might suggest is determining if there is really a drain, or if the drain is from lack of use.

If you have access to a quality meter (with a milliamp setting) disconnect the battery at the ground, then bridge the meter between the ground post and the ground cable. If there is a drain (with meter set to milliamps), it will show up. If you find a small drain, start removing the fuses one at a time and check for the drain. This will at least determine if there is a drain, and on which circuit.

On my Loader, I finally narrowed it down to a ‘failing’ Motorola radio that was pulling power when off. The drain was 4 milliamps, and without a quality meter I would never have found it.
__________________
82 380SL 41K miles sold, 98 SL500 44K miles, 13 C300 4Matic, 14 CLA-250 4Matic
Reply With Quote
  #12  
Old 02-11-2010, 09:31 PM
have mercy's Avatar
Registered User
 
Join Date: Dec 2007
Location: Hedgesville WV
Posts: 200
Remove fuse and use a meter and test both ends where the radio fuse goes. Use the amp setting.If it moves,than unhook power from radio, if it still does its in the car if not the radio.If you still can't find,Remove all fuses. Remove + from battary,install amp meter between battary and cable. Make sure everything is off. Start installing fuses 1st the ones that stay hot all the time,.And then the rest,when amp meter jumps thats the problem.
__________________
30 yr's still in love
Reply With Quote
  #13  
Old 02-12-2010, 12:59 AM
Registered User
 
Join Date: Dec 2000
Location: Battle Ground, WA
Posts: 576
I installed an inexpensive battery maintainer in both my '79 450SL and my 2001 ML320. Harbor Freight sells a unit that will sit right next to the battery and directly connect to it. It is a three stage charger with an anti-sulphation mode on the trickle charge, and has kept my batteries up really well. Without the maintainer my ML320 would go dead in less than two weeks, and the 450SL would be dead in about 3 months. I ran a short extension cord out the front of the grille and just plug in the car when I park it. HF regularly sells the units for around $20 on sale. They are switching units, seem to work very well.
__________________
Richard Wooldridge
'01 ML320
'82 300D 4.3L V6/T700R4 conversion
'82 380SL, '86 560SL engine/trans. installed
'79 450SL, digital servo update
'75 280C
Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

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




All times are GMT -4. The time now is 04:11 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2018 Pelican Parts, LLC - Posts may be archived for display on the Peach Parts or Pelican Parts Website -    DMCA Registered Agent Contact Page