Need Car Help

[Macs]

I am a little stumped on this one. 2 weeks ago my wifes battery was dead on her expedtion. I cleaned the positive terminal cause it was filthy and jumped it off of my car. It then didnt have a single problem all week. Come last saturday, she tried to start it and the horn started blowing. It wouldnt do nothing. So i thought it must be the battery. I hooked a charger up to it and then we took my car to a local festivel. Sunday morning i went to start it up and drive down to the auto parts store. I was just going to replace the battery there. Well it did the same thing. As soon as i opened the door the horn started blowing and the security light was blinking. So i took out the battery and went down to the auto parts store. They checked the battery and said that nothing at all was wrong with it. So i brought it back home and cleaned all the connecting points really good. Put the battery back in and the same thing. So i searched online and found that the imobilizer was activated and learned how to turn that off. Then it cranked right up. She has drove it all week and i thought maybe i fixed the problem since i cleaned the connection points. Then this morning the batter ywas dead again...... I am now wandering how good the auto part store battery tester was.

[seantrx250r]

my suv did the same thing it was because i didnt solder the wires on the cable once i did it has not had a problem 2yrs and nothing gone wrong

[Mosh]

You need to have the truck checked for a parasitic draw.Something staying on and killing the battery.
I have done a few Explorers,where the factory radio amp stays powered up,after you shut the truck off.

[Macs]

You need to have the truck checked for a parasitic draw.Something staying on and killing the battery.
I have done a few Explorers,where the factory radio amp stays powered up,after you shut the truck off.


i WAS SCARED IT WAS GOING TO BE SOMETHING LIKE THAT. iS THERE A WAY FOR ME TO CHECK THIS MYSELF?

[Mosh]

Well,the old school way was to take a test lite and disconnect your negative cable,and hook the test light in series between the cable end and the negative post on the battery.
If the light lit up,then something was drawing the battery.

But with the advancement in cars,many vehicles will draw up to 1 amp for as long as 1-2 hours,until the body control module powers down the system.Enough to light a test lamp,but wont give you accurate current draws.

That being said, There is a special adapter that goes on the cable,and you hook your amp meter to it.Shut the truck off,then flow current thru the meter and adapter, and monitor it.

Most cars will start out drawing 500 miliamps(or 1/2 amp) for up to 45 minutes,then as each module powers down,you will see the draw diminish until about 50 miliamps.That could take up to 2 hours to show up,until all modules power down.
After 2 hours,no vehicle should draw more than 50 miliamps,or it will kill your battery over nite.

Therefore,the old test light method,is not a accurate way to test.
Once you verify there is a draw with the amp meter,then you have to pull one fuse at a time,until you verify what system is creating the draw.
Then you have to isolate what in that system is causing it.

For instance,If you pulled your memory seats system fuse, and the amperage dropped to a low level, it could be the module,or a shorted switch in the memory seats.
Or if you pulled the radio fuse,and the amperage dropped, then it could be the radio, or the factory amp for the radio etc..

It is very complicated work to do, without the proper knowledge, or tools and wiring schematics..Many newer cars have up to 12 modules or systems on them that have to be isolated.There is no (miracle tool) that you can plug into a car and it tells you the exact problem.Contrary to what AutoZone or other people believe.

That is why it is so damn expensive to have your vehicle repaired anymore.LOL

If I were you,I would take it to a reputable shop that specializes in Diagnostics,and pay the 80 bucks to have it diagnosed.
Unless you want to longshot it, and throw a battery in it...You may fix the problem or not with a battery.

I dont know if they tested your battery correctly or not...If it was tested properly,and it is a newer battery,then I doubt it will fix your problem.

Most of those guys at AutoZone and the like,are one step up from Taco Bell workers,and have very little knowledge about cars.No offense anyone.

Make sure the alternator is putting out good,and check all your dome lights,glove box lights ect,and make sure they all shut off as designed. Check the vanity mirror lights in the visors. Women like to leave them swicthed on while putting on thier make-up....LOL

Also Check and make sure the wife or kids didnt leave a cell phone charger, gameboy chargers etc, plugged into one of the Auxillary lighter sockets. I have seen that alot.

From the sounds of it,since your theft deterrent sysetem was acting funky,I suspect a bad door latch swicth which is VERY VERY common on Fords,
Usaually the driver door latch causing the problem,since it gets most of the abuse.

[Macs]

Thanks for the info. I am going to try the draw test tonight. I have read up and gotten a few step by steps. Also i have researched the battery testing and it appears there is alot of batteries that are bad that test good. So i have a step by step procedure on testing that also. Now thinking back, when i brought the battery to be tested it had been on a 2 amp charge for 24 hours. So that might have interfered with it.

[smokinwrench]

I don't trust these new digital battery testers at all. The best battery tester is the old carbon pile resister type where it puts a draw on the battery to see if it will carry a load.

If your still getting a draw after a couple hours wiggle the ignition switch.

[Daddio]

From the sounds of it,since your theft deterrent sysetem was acting funky,I suspect a bad door latch swicth which is VERY VERY common on Fords,
Usaually the driver door latch causing the problem,since it gets most of the abuse.


I will agree with what moshman said about the door latch switch. I had a Taurus that had that problem. I just pulled the fuse and lived with no interior lights.

[Macs]

It ended up being the battery. I will never trust the O'rielly's tester again. I did the pasatic draw test and it came back fine. Started doing my own battery test from an online forum and it failed the second step. I then took it to Autozone and in 38 seconds there tester said bad. All of this work cause oriellys tester sucks.