New Battery, dead after 2 weeks, 1996 Contour

[Whimsey]

I replaced an 6+ year old AAP battery because it was stone dead after sitting ~3 weeks unused. It was kept on a maintainer during the winters and ran for a couple of months this year afterwards without issues. I figured the battery was just getting near the end of it's life. Bought a Motorcraft Battery and trickle charged it before I installed it. All was good voltage was 12.6 with the vehicle off. It started immediately for a couple of weeks, even letting it sit for a day or two without use. It sat for 3 days without use and was totally stone dead again. The Contour is a "primitive vehicle" by today's standards so I can't imagine a huge parasitic power draw over 3 days instead of 2 days to totally kill the battery all of a sudden without warning??? If I can charge it up with my trickle charger I'll see if there is a large parasitic draw with the vehicle off. My other thought is it's just a bad made JC Mexico battery that died shortly after beginning it's use. What a pain it's blocking my "working" vehicle in the driveway.

Whimsey

 

[WobblyElvis]

Charge up the battery and start the car. With engine running the voltage at the battery should be over 14 volts. This will confirm the alternator is charging the battery.

Eric the Car Guy has a good parasitic troubleshooting video.
https://youtu.be/KF1gijj03_0

 

[Donald]

Well something left on? Alternator not charging?

 

[javacontour]

Trunk or glovebox light?

IIRC, the trunk light switch was a commonly broken item, leaving the light on all the time.

 

[Colt45ws]

There is a parasitic draw somewhere. As Java suggested, a broken light switch is probable, but anything could be. Maybe a short inside the radio is drawing it down, seen that before.
Meter out how much draw you have and go from there. Start pulling fuses.

 

[javacontour]

Yep, that's essentially the path to a solution.

Need to know what the specs are for the normal Key Off current draw. If it's higher, then you have to start pulling fuses.

Don't forget the alternator. A bad diode bridge in the alternator may also be the source of a parasitic current draw. So I'd also have the alternator tested...

Originally Posted By: Colt45ws
There is a parasitic draw somewhere. As Java suggested, a broken light switch is probable, but anything could be. Maybe a short inside the radio is drawing it down, seen that before.
Meter out how much draw you have and go from there. Start pulling fuses.

 

[Colt45ws]

I'd say on something like that, more than 250ma I'd be suspicious of. I mean the only thing that should be drawing power is PCM keep-alive and the memory/clock on the radio. But I estimate that your draw is quite a bit more than that based on how long it took to discharge.
So the reason why it started on the 2nd day, but not on the third is because capacity is all in the first few volts that are discharged. By the time the battery hits about 10-11V there is no capacity left and it will fall rather rapidly from there.
Plus we dont know its state of charge when it was parked prior to its 3 day sit. If it wasnt fully charged that will make matters worse. Was it a long drive, or was it a quick run to the local stop-n-rob? As well, if the alternator is shot as suggested, then it probably wasnt 100% even with a decent drive.
This is an excellent use case for one of those little hall effect clamp meters. Ive tried to break into a vehicle circuit god knows how many times with a meter and blown almost as many 10A fuses inside the meter.

 

[Kawiguy454]

Check door switches, not uncommon for them to need adjustment and not shutoff when door is closed. Make sure the dome light goes out before the door fully latches.

 

[Donald]

Twice on my Subaru Forester the battery died (at least a year apart). Charged it on AC charger and good to go. Never figured out what was left on. Of course I did not blame myself.

So I would first charge on AC charger and see what happens. Obviously be prepared.

 

[bbhero]

^^^^^^^^^

Really good answers and help by the guys on here.

 

[Whimsey]

Thanks for all your great responses, lots to check on. I left the battery at Ford and they tested after charging overnight, it was reading .09 volts when I brought it to them. They said after it was charged they ran their tests on the battery and it checked out ok. I got it back, 12.96 volts, and will put it in only temporarily tomorrow to check on simple possible draw issues. I know the interior lights go off. Can't swear if the glove box & trunk lights go out, will check when I hook the battery up tomorrow. I'll see if I can test for the parasitic draw with the vehicle off and how much the alternator raises the voltage at idle. If I strike out I'll it's off to my mechanic next week. BUT I'll disconnect the battery after my testing tomorrow so as not to drain it before I can get to the mechanic next if I don't find the problem. Again a MILLION thanks for all your help. BITOG is a tremendous site

.

Whimsey

 

[Traction]

You can tell a lot just looking for how small, or big of a spark you see by disconnecting the negative terminal, and before if any capacitors discharge, lightly touch the terminal to the post. If you have a bulb on, you should see a noticeable sparking/arcing. More amps make more sparks, and you should if any might see a flicker at the most.

 

[eljefino]

I had a 97 contour and one of the relays stuck closed in the under-hood fuse box. As a result the ignition module buzzed quietly. I switched the relay with the identical horn relay and everything was kosher after that.

I'd go through, pulling relays with the key off. See if any "click" in your hands when removed. Pick a cool night when the car's been sitting-- even put it on a trickle charger-- and aim an infared thermometer at various things like the IGN module, computers, alternator, see if anything is above ambient.

Also take note this car was notorious for falling-off insulation made from some hippy soy junk.