something draining the battery... im out of ideas..

[fast68]

ok recently in the past couple weeks i have noticed that when the car sits a few days not driven the battery gets totsally drained dead.

i changed nothing, did nothing new anywhere.


i looked in the trunk, glovebox, and under dash etc for any light. and there is no hood light or dome light currently.

pulled every fuse and relay

and still the same draw on it

i made a small 12v light bulb thing to put between the battery post and battery cable end

it stays lit continuously regardless of what i try unplugging or removing in the car


i am at a loss


is there something common in these 94-97 corollas i am overlooking that may be drawing ??



thanks

[lee777]

Power antenna?

[retiredat44]

brake lights swtich?

the alternator can do that too..

[TrailDust]

Have you checked the cigarette lighter? I've seen more than once where a deteriorating gasket has caused the lighter to be the battery drain source.

[mvftw]

Originally Posted by retiredat44

the alternator can do that too..

I had a bad alternator cause that...

[fast68]

hmm lighter is a good idea for sure! but i would think pulling all the fuses would have killed power to it right? i would imagine. no ?



hmm ill check it out and see..

brake light switch possibly bad even if its not making the lights stay lit all the time ?



alternator hmmm

the only thing i tried with the alt was unplugging the harness to it and that changed nothing as well.




maybe i can try pulling the batt 12v source to it ?

hmm


also pulling the wiper motor harness did nothing as well


antenna is not power one


another thing is that i leave the key in the ignition switch 24/7

ther eis no possible way it would od anything in lock position to draw on the batt would it?

ive owned over 200 vehicles now and never had such an issue caused by leaving the key in so i dont know about that..

thanks!!

[hungt1999]

how old is your battery? an old battery can lose its charge on its own

can you connect an ampmeter in series with the battery and see if there is a current flow?

[fast68]

two years old


all i have is a digital multi tester

would that work ?


what about the ECM or PCM?
how much should it be pulling? if any?
with car turned off

i still need to go check cig lighter and such


thanks

[hungt1999]

Originally Posted by fast68

two years old


all i have is a digital multi tester

would that work ?


what about the ECM? how much should it be pulling? if any? with car turned off

i still need to go check cig lighter and such


thanks

You need a multimeter that can read Amperage.

I would disconnect one of the two battery terminal and wire the multimeter in series between the battery post and the original battery wire and see how much current is being drawn with everything OFF.

make sure to know how to use the multimeter correctly to measure amperage. The internet has plenty post showing you how to do it.

Warning: don't crank or run the engine or have any other source such as head lights, fans, etc. with this set-up, this is for diagnostic purpose only to find out the parasitic drain. When you crank the car, the current draw is very large and it will possible blow a fuse in your multimeter or damage it

Normally, I would estimate a current drain of a few milliwatts should be present to keep things like the clock and ECU memory running.

[fast68]

I would disconnect one of the two battery terminal and wire the multimeter in series between the battery post and the original battery wire and see how much current is being drawn with everything OFF.

thats what ive bene doing with the small 12v light bulb i have.
between the neg cable end and the neg batt post.

anyways i found the culprit a minute ago..


alternator!

i removed the charging post cable from the alt and no more draw!

dammit.

time to yank the alt..

had alt problem on the 88 pickup as well

it kept burnign up brushes

so i ended up rigging an old 70s chevy alt on it

worked like a charm ever since then and so bright lights!

might be doing the same to this car it looks like


now that i think about it the car has no hood

maybe rain shorted the alt

possibly?

may be my own fault..

never have this problem with the gm alts. water never hurts them.

ive owned a million with no hoods and never a problem over the years

maybe toyota alts are not waterproof..


and i know they are not oil proof because the pickup one died due to being soaked with oil all the time


maybe i could just put a switch in the charge wire... hmm..

for now at least..

thanks,.

[lee777]

Possibly a shorted diode allowing reverse current.
Time for an alternator rebuild kit.

[retiredat44]

I also had a problem once with an aftermarket set of fog lights. I had to put an secondary cutout switch on the battery power wire to the fog lights relay. I did this to fix a battery drain problem because of an aftermarket fog lamp and relay setup.

I think the relay was draining the battery after a couple days when the van sat. I think the aftermarket relay dpdt was switched on but the secondary part had no juice switched on to allow the lights to come on.

Being that first set of contacts being on on the first pole dpdt had that small bit of current running through it, which was just enough drain to only be noticed after a couple days of not running the van.


Bottom line, does the car have any after market electronics? Even an aftermarket radio can be wired wrong.

[1jzdreamer]

Toyota alt's are waterproof.
Ive had one melt itself but never have one fail due to water.

[Rip The E Brake]

You should really cover the car...

[gold94corolla]

LOL.... well, my battery kept dying because the trunk light wouldn't turn off when the lid closed....but it's working now.... and you need a new battery for darn sure!