Battery drain, what a pain - Automotive Wiring and Electrical


	Auto Repair Home	SEARCH POSTS	WHO'S ONLINE	LOG IN

Automotive Repair

Car Troubleshooting Topics
  Car Troubleshooting
  Engine Troubleshooting
  Engine Fault Codes
  Electrical and Wiring
  Transmission Problems

Car Repair Topics
  Car Making Noises
  Car Stereo Repair
  Heating or AC Issues
  Motorcycles and ATVs
  Tricks of the Trade
  Truck Repair Advice

Site Options:
  Login
  Sign up here!

Latest Forum Post

1989 toyota pickup 3.0 crank no start

I have a 1989 toyota pickup 3.0 crank no...

Strut spring orientation and strut mount tension nut

2017 Nissan rogue awd 2.5 L Put in Monro...

Transmission stuck in part, I have tried everything

So I'm working on my elderly fathers 201...

2017 dodge journey LED headlights on/off randomly

Year of vehicle 2017 Make of vehicle dod...

Kia Soul starter replacement issues!

Okay so my car is a 2010 Kia soul 2.0 en...

Please Help - Knock sound & engine fail

Hi all, Hoping to get some insight and ...

multiple warning lights

2013 GMC Terrain 130,000 miles 4 cylinde...

03 alero no low speed blower

Good day everyone, I have a 2003 Olds a...

04 Chevy 2500hd tail light issues

Help!!! I have changed my combo switch...

1999 Grand Caravan Sport not starting.

Hi. I'm new here. I hope someone can hel...

Battery drain, what a pain

Sign up here!

Search for (search options)

Auto Repair Home>> Automotive Repair>> Automotive Wiring and Electrical

Shade Tree
New User

Oct 16, 2007, 7:59 PM

Post #1 of 3 (1714 views)

Battery drain, what a pain	Sign In

Been working on this one for a week or so.
92 S-10 Blazer, battery died 3 months ago, everything fine with a new one, then it went dead again recently. Charged it up, next day after work it's dead again. Jumped it & went straight to chain auto parts store where I bought the battery. Thay tested it, not charged enough to load test, but alternator only doing 8 amps (85 normal). Replaced that, no improvement.
Began to trace wiring, found a short from the alternator battery terminal to alt casing - 105 k ohms, enough to throw a small spark when connecting wire. This isn't normal, right?
I also get 12V between positive battery post and and disconnected pos cable (with alt disconnected) - figured that was the always hot lead to my stereo or something small since it doesn't even register on my DC ammeter.
I'm guessing my new alternator is grounded, but want some confirmation before I try to return it.
Thanks in advance for your help!

Tom Greenleaf
Ultimate Carjunky / Moderator
Tom Greenleaf profile image

Oct 17, 2007, 2:15 AM

Post #2 of 3 (1708 views)

Re: Battery drain, what a pain	Sign In

The noted drain is the problem and likely within the alt itself. Double check that everything is off in the vehicle - some sneaky things are glove box lights, cargo/trunk - things like that and even delay interior lights must stay off when checking. Don't forget the hood light too.

Always best to charge batteries with a charger and not the alternator when possible. A battery can kill the alt and vs versa so both need to be good at the same time,

T

way2old
Veteran / Moderator
way2old profile image

Oct 17, 2007, 4:43 AM

Post #3 of 3 (1704 views)

Re: Battery drain, what a pain	Sign In

You can not detect a current draw by ohms or volts. If you disconnect the battery and place the meter in series on the volt scale, you had better be getting battery voltage. This is because all the battery grounds are connected and you are completing a circuit. You need to do the same test with amperage. A current draw as small as a tenth(.10A)of an amp can run the battery down in a few days. So use the current function on a meter and csee how much current you are drawing.

Being way2old is why I need help from younger minds

Search for (options) Privacy Sitemap