Check for "key-off" short - drains battery

TIMTREE

MEMBER
1999 TOYOTA CAMRY
82,000 MILES

I am looking at a 1999 Camry for my son. When we went to see it, a new battery had been drained after sitting (key off/out) for 1 week. Owner says mechanic says it was a bad battery, and replaced the batter under warranty. I suspect a "key off" short.

How can I check for that when I go back to see it? Will disconnecting the ground cable and checking with a multimeter (amps) work?

Thanks.

5 Replies

WRENCHTECH

MECHANIC
20,758 POSTS

There is a procedure for finding a battery draw like that.

You will need a digital ammeter and a jumper wire with clips on the ends to do this.
First rig any door switches so you can have a door open without triggering the interior lights and unplug the hood light. Remove one battery cable and attach the meter in series between the battery cable and battery post. Take the jumper wire and also attach it the same way. Leave the jumper wire on for at least 10 minutes to expire all the automatic timers. Now remove the jumper wire and read the meter. Anything over 50ma is too much draw. The way you locate this is to start removing fuses one at a time until the meter drops to normal level. This will be the circuit with something staying on. Determine what components are part of that circuit and check them individually until the problem is isolated.

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Friday, January 28th, 2011 AT 4:43 PM

TIMTREE

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3 POSTS

Wrenchtech, thank you.

I actually got a similar answer on the Edmunds forums. I had to move there, this site is too hard to navigate. This site needs an upgrade in user friendliness.

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Friday, January 28th, 2011 AT 4:53 PM

THIS IS MIKE

MECHANIC
686 POSTS

Thank you for your feedback, we will do our best to make the site easier to navigate. Currently after you ask a question you can find all of your replies by clicking your member name and view your profile page. When there is an answer to your question you will also get notified at the email address you sign up with. I hope we can help you next time.

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Sunday, January 30th, 2011 AT 12:54 AM

TIMTREE

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3 POSTS

Mike my main issue was, for the life of me, I could not figure out under what forum/category I was posting my question. I think my question, or at least my first attempt at it, ended up as a reply to someone else's question.

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Sunday, January 30th, 2011 AT 2:52 PM

THIS IS MIKE