Battery drain 72 hours, altenator/battery tested and good, any ideas?

[kaelc]

2003 Vibe GT, no accessories and the battery drains in about 72 hours. Let it sit from Christmas eve and tried to start it boxing day and no dice. Been doing it about a month, resulting in 4 jump starts. The battery was tested using a Snapon battery tester.There is a small "click" sound that happens every few minutes in the engine compartment. A mechanic suggested a relay but said he had no place to start looking. Any ideas out there?

[Salsa Guy]

Parasitic power drains are a pain to find. The best bet is take it to someone who specialize in Auto Electrical systems. It took me a long day to find my daughter's issue in her Tarus.

[joatmon]

You say the battery tests ok, how old is it and are the terminals clean?Other than batteries, and inadvertently leaving something on, the only recurrence of a battery draining issue was that there was a problem with some of the early models turn signal switch assemblies, where a bit of moisture and cold weather could cause the headlights to come on when the car was off/unattended. You probably would have noticed if that was happening to your car, Does it take three days for the battery to drain to the point where it won't start, or is that just the chance timing of when you've had the problem come up?Once you do start it, do you get a chance to run it long enough to fully charge the battery?

[jayman2009]

try disconecting the battery for a fue days see if it loses a charge. had a van at work like that after 2 days battery would go dead. tested fine tho. disconected it and 2 days later was dead. ended up being awonkey cell

[kaelc]

We replaced the terminals and the battery is less then three months old.

It turns out when we pull the EFI 15A Fuse the drain goes away. You can also hear several relays switch off when you pull the fuse. Any idea what I should disconnect next, I did try switching out the EFI relay in the fuse box and it didn't have an effect?

[bluneon]

disconnect the neg terminal from the battery. use a good multimeter. tie the black end to the battery post, tie the red end to the battery clamp you've just disconnected. set the meter to measure amperage. what you are attempting to do is determine the amount of excessive draw that something in the car is pulling, something is staying on when it should go to sleep.

the hood is obviously open, set the hood latch. take the key out of the ignition, close all doors and lock the car. the good thing is these cars go to sleep within minutes. watch the meter for how much amperage the car is pulling from the battery. excessive draw is .05 amps or more. a good system reading is anything lower than .05 amps. the closer to 0 the better.

the car will be asleep after a few minutes. when you don't notice any further dropping of amperage after the few minutes, pull that 15a efi fuse you've identified earlier. if the reading falls to sleep readings then you've found the faulty circuit.

pull up the wiring diagram for the efi circuit. what you have to do now is inspect every component and wire within the system.

replace the fuse, repeat the draw test after disconnecting one component at a time withing the circuit. the last part disconnected that brings the amperage within good levels is the component that is not going to sleep.

wiring issues are another story.....

complicated or not?

[Salsa Guy]

I have drawings for a Base vibe but not the GT. The EFI supplies a constant +12v to the PCM/ECU to maintain the memory. If you are hearing relays drop out after pulling the fuse it sounds like the EFI relay is still being held in by the PCM/ECU. It's possible the relay could be bad ($10 part) but unlikely. It's also possible, for what every reason your ECU, is not going to "Sleep". On some cars it takes some time for that to happen, 10 minutes or more. So your test on pulling the Fuse maybe usless.

I think I stated this several months ago, before you start swapping parts take it to someone the specializes in automobile electrical systems. You will be flying blind unless you have the electrical diagrams, know how to read them and can use a DVM. Tossing parts at a car can get $$$ and very frustrationing especially with electrical systems.

[dpetepiece]

My 2006 base Vibe had to have the engine computer replaced. The check engine came on. If the computer is malfunctioning it could do weird things like trying to maintain pressure in the fuel injection system.

Dave p

[kaelc]

Thanks everybody, especially Dave P. Taking it to an electrical specialist was a costly mistake as he only confirmed what Dave posted. The solution other then installing/buying a new computer was to install a fuse switch which runs to the dash and is now an extra security measure. Probably cost you a $20 to install yourself, $100 at car radio place or $250 at the "Electrical specialist". Thanks again everyone, and if anyone has the same problem, I can email you pictures of the solution.

[MrKnwn2ActBad]

Being an audio guy and seeing this issue with a lot of "GM" cars.....check the radio. Most of the time when you have this issue the radio has gone bad and wont shut off when the key is off. When you get out of the car check to see if you hear a slight sound coming from the speakers. If its like my Vibe was the display was shot on the radio along with most of the lights and you couldnt tell if the radio was on or off. Hope this helps