Notices
928 Forum 1978-1995
Sponsored by:
Sponsored by: 928 Specialists

Battery Drain Help Needed

Thread Tools
 
Search this Thread
 
Old 11-05-2009, 01:10 PM
  #16  
LGL
Instructor
Thread Starter
 
LGL's Avatar
 
Join Date: Oct 2008
Location: Virginia Beach
Posts: 194
Likes: 0
Received 0 Likes on 0 Posts
Default Answers

For Korwen: Good question. I removed alternator then lifted jump post and still had reading. Somewhere in my failing memory it seems when I first lifted leads at jump post with the alternator still connected, the drain went away.

For Alan: Measuring with digital multimeter in series between battery ground cable and chassis; removed all "extra" leads to positive post with no change; Sequence: alternator-jump post-starter; all are functioning except the overhead but that is a long standing problem and the battery drain is new. Also I started by pulling all fuses one at a time.

Davek9: 1986 Auto with ABS.

Thanks,
Grant
Old 11-05-2009, 01:41 PM
  #17  
LGL
Instructor
Thread Starter
 
LGL's Avatar
 
Join Date: Oct 2008
Location: Virginia Beach
Posts: 194
Likes: 0
Received 0 Likes on 0 Posts
Default Current Status

Alternator disconnected, jump post leads lifted, starter disconnected except top yellow lead to solenoid. Drain is > 2 amps. At one point I also pulled the X relay with no effect.
Old 11-05-2009, 08:53 PM
  #18  
davek9
Rennlist Member
 
davek9's Avatar
 
Join Date: Jul 2006
Location: Bloomfield, MI
Posts: 5,113
Received 327 Likes on 179 Posts
Default

Have U tried disconnecting the main Power lead on the Drivers Side Front fender that goes to the ABS System?
Old 11-06-2009, 01:25 AM
  #19  
LGL
Instructor
Thread Starter
 
LGL's Avatar
 
Join Date: Oct 2008
Location: Virginia Beach
Posts: 194
Likes: 0
Received 0 Likes on 0 Posts
Default Reply

No but I'll try it today.
Old 11-06-2009, 02:00 AM
  #20  
Alan
Electron Wrangler
Lifetime Rennlist
Member
 
Alan's Avatar
 
Join Date: Mar 2002
Location: Phoenix AZ
Posts: 13,371
Received 398 Likes on 272 Posts
Default

I dont undestand - if the battery extra connections are remove and the starter is disconnected - what the heck is the battery+ connected to? it shoud be NOTHING...

Alan
Old 11-06-2009, 12:05 PM
  #21  
LGL
Instructor
Thread Starter
 
LGL's Avatar
 
Join Date: Oct 2008
Location: Virginia Beach
Posts: 194
Likes: 0
Received 0 Likes on 0 Posts
Default Reply

Still connected is the main power cable that goes forward .
Old 11-07-2009, 01:47 PM
  #22  
Alan
Electron Wrangler
Lifetime Rennlist
Member
 
Alan's Avatar
 
Join Date: Mar 2002
Location: Phoenix AZ
Posts: 13,371
Received 398 Likes on 272 Posts
Default

That goes to the starter - if the starter main connections are removed it goes nowhere...

Alan
Old 11-09-2009, 01:10 PM
  #23  
LGL
Instructor
Thread Starter
 
LGL's Avatar
 
Join Date: Oct 2008
Location: Virginia Beach
Posts: 194
Likes: 0
Received 0 Likes on 0 Posts
Default

One last question. Drain is coming from the aux lead on the + battery post ( permanent lead, not the add-on stereo). The lead disappears into the body. What does it go to ?

An interesting aside. When my crawler hung-up and my chest was rubbing the oil pan, I discovered that even a retired submarine sailor can be claustrophobic. I guess I should be happy it was my chest and not my belly.
Old 11-09-2009, 06:28 PM
  #24  
WallyP

Rennlist Member
Rennlist Site Sponsor

 
WallyP's Avatar
 
Join Date: Jun 2001
Location: Acworth, GA
Posts: 6,469
Likes: 0
Received 11 Likes on 11 Posts
Default

LGL - On the '86, there should be three medium-sized red wires on the battery positive terminal. One feeds the fuel pump relay, one the EZF (ignition) relay, and one the LH (injection) relay in the Central Electric Panel.
Old 11-09-2009, 06:47 PM
  #25  
davek9
Rennlist Member
 
davek9's Avatar
 
Join Date: Jul 2006
Location: Bloomfield, MI
Posts: 5,113
Received 327 Likes on 179 Posts
Default

Wally or Alen, where does the Power wire for the ABS unit come from?
I thought that could also be a source for a drain and it was unfused, just like the Jump post on the passanger side.
Just courious

Thanks!
Old 11-09-2009, 09:02 PM
  #26  
LGL
Instructor
Thread Starter
 
LGL's Avatar
 
Join Date: Oct 2008
Location: Virginia Beach
Posts: 194
Likes: 0
Received 0 Likes on 0 Posts
Default

Thanks Wally,

3 red is correct but pulling the 3 relays didn't kill the drain so it must be something grounding before it gets to the relays. Tomorrow is another day.
Old 11-10-2009, 10:38 AM
  #27  
WallyP

Rennlist Member
Rennlist Site Sponsor

 
WallyP's Avatar
 
Join Date: Jun 2001
Location: Acworth, GA
Posts: 6,469
Likes: 0
Received 11 Likes on 11 Posts
Default

The heavy red wire runs from the jump start post to the ABS unit, so that is a heavy, unfused direct battery connection.
Old 11-10-2009, 05:27 PM
  #28  
Alan
Electron Wrangler
Lifetime Rennlist
Member
 
Alan's Avatar
 
Join Date: Mar 2002
Location: Phoenix AZ
Posts: 13,371
Received 398 Likes on 272 Posts
Default

On most models (including I believe an '86) it runs from the alternator to the ABS distribution point (similar to the jump post) on the drivers side fender near the radiator. It is indeed unfused so be careful with it (don't do any arc welding with it...).

I think you need to be methodical and document what you are doing as you go. Start with a good understanding of the connectivity.

Battery + goes to the items Wally noted directly as well as the starter, the starter is connected to the alternator main terminal, that terminal is connected to the jump post and seperately to the ABS distribution point. The jump post connects to the top of the central electric (fuse) panel (3 parallel wires) and thereby directly to all the always on fuses - though the panel & via the ignition switch & back for all the switched (igniton and accessory) fuses.

Step one disconnect and isolate all the connections at the jump post - do you still have leakage? if yes disconnect both seperate smaller feeders from the battery post - do you still have leakage? if yes the leakage is in the starter/alternator or ABS - isolate which one by further experiments.

If you eliminated the leakage via step 1 of this path then the leakage is in the central electric connections, if you eliminated it via step 2 its in the ECU/fuel pump connections.

You need to get to this level of granularity first....

It seems what you have been doing so far has been a bit random... you need to understand what each test tells you so you can focus in more & more on the suspect area.

Alan
Old 11-10-2009, 05:33 PM
  #29  
oz928s4
Racer
 
oz928s4's Avatar
 
Join Date: Oct 2008
Location: Northern Territory, Australia
Posts: 361
Likes: 0
Received 0 Likes on 0 Posts
Default

There is a little tool calle a Fuse Buddy which allows you to check drain on each electrical circuit thru the fuses...maybe
Old 11-10-2009, 05:54 PM
  #30  
Alan
Electron Wrangler
Lifetime Rennlist
Member
 
Alan's Avatar
 
Join Date: Mar 2002
Location: Phoenix AZ
Posts: 13,371
Received 398 Likes on 272 Posts
Default

I would always start with the gross identification of the leakage domain.

Chasing individual fuses when its not clear that it is actually any of them... is a very time consuming activity...

I have a fuse meter similar to the one you describe - but I certainly would not be using it at this point... It has its uses for sure and is a good tool - just not for initial diagnosis like this...

Alan


Quick Reply: Battery Drain Help Needed



All times are GMT -3. The time now is 03:28 AM.