Picture shows a typical multimeter showing separate fuse-protected inputs for current scales:
Battery drain issue
Thread Starter
Cruising
Joined: Jun 2016
Posts: 10
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Battery drain issue
I am having an issue with my battery draining. Even after being on charge all night, car won’t start. Battery tested ok, but put a new battery in last night and drove with no issues. Car wouldn’t start the next morning. Any ideas?
Last edited by Red14me; Apr 30, 2018 at 10:35 PM. Reason: simplifying post
Melting Slicks
Joined: Sep 2008
Posts: 3,142
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From: Espanola New Mexico
First thing to do is disconnect negative battery cable and connect DVM in series with negative battery cable and negative battery terminal. Select DC amps on meter and measure sleep mode current after 15 minutes or so, sleep mode current should be about 25-30 milliamps. Common issues that cause excessive current drain can be power seats, audio amps, alternator, and headlight modules, of course you can pull fuses observing DVM while doing so, hope this helps.
Pro
Joined: Jan 2005
Posts: 644
Likes: 17
From: O'Fallon MO
First thing to do is disconnect negative battery cable and connect DVM in series with negative battery cable and negative battery terminal. Select DC amps on meter and measure sleep mode current after 15 minutes or so, sleep mode current should be about 25-30 milliamps. Common issues that cause excessive current drain can be power seats, audio amps, alternator, and headlight modules, of course you can pull fuses observing DVM while doing so, hope this helps.
Mike
Pro
Joined: Jan 2005
Posts: 644
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From: O'Fallon MO
I would double check the lead connections on your multi meter to make certain they are set up to measure amps............
If the leads are correct you may have to step down to a scale less than 10A. The draw should be small and not knowing which meter you are using you may have selected a scale too high to sense the normal small draw.
If the leads are correct you may have to step down to a scale less than 10A. The draw should be small and not knowing which meter you are using you may have selected a scale too high to sense the normal small draw.
Thank you,
Mike
Melting Slicks
Joined: Sep 2008
Posts: 3,142
Likes: 803
From: Espanola New Mexico
Most likely that the fuses for both amp current ranges are bad, since the meter is connected in series when measuring current there are two internal fuses to protect the meter in case of very high current draw, I would open the meter and check the fuses, might save you the cost of a new meter.
Pro
Joined: Jan 2005
Posts: 644
Likes: 17
From: O'Fallon MO
Most likely that the fuses for both amp current ranges are bad, since the meter is connected in series when measuring current there are two internal fuses to protect the meter in case of very high current draw, I would open the meter and check the fuses, might save you the cost of a new meter.
Thank you for your help.
Mike
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Pro
Joined: Jan 2005
Posts: 644
Likes: 17
From: O'Fallon MO
Most likely that the fuses for both amp current ranges are bad, since the meter is connected in series when measuring current there are two internal fuses to protect the meter in case of very high current draw, I would open the meter and check the fuses, might save you the cost of a new meter.
Mike
Pro
Joined: Jan 2005
Posts: 644
Likes: 17
From: O'Fallon MO
Replaced the two fuses and now I get a reading of .02 on the 10 amp scale which I assume is 20 miliamps. So I guess I don't have a draw after all just a week battery maybe, I would have thought the battery would have held up after 2 weeks as it's less than a year old.
Mike
Mike
Melting Slicks
Joined: Sep 2008
Posts: 3,142
Likes: 803
From: Espanola New Mexico
Yes moving the decimal point three places back will give you 20 milliamps which is with in spec for sleep mode current draw. I would have your local auto parts store charge and load test your battery before buying a new one just in case, not unheard of thou that sometimes you can buy a new battery that will fail within a year or two.
