Battery dead, or alternator, or what?

[MyEclipse5]

ok my car hasn't been run n like 2 montsh(cause im 15) and its dead, we jumped it and it ran fine, wheels scraped a lil, but it was ok. Well when we shut it off it'll start just fine but like 7 days later its dead again. and i meen NOTHING. The amp and radio is off so its not that and i think we jsut got a new bat. and alt. so what can it be....maybe since it sat for so long its like dead or what?

 

[Doug99RS]

It sounds like there's alot of down time for your car. You mentioned that twice it's sat for several days (two weeks at a time right?). So if you can't find a draw like that then you may want to disconnect one of the battery terminals next time you park it for a while. If the battery still won't crank the car when you get back you'll need a battery. If the battery is good then you've got a draw somewhere OR you're draining the battery, while driving it, right before you park if for a while.

A few more things to check...
-What is your voltage reading across the battery terminals WHILE the car is running?
-Do a voltage drop test on each terminal and see if you've got a tight but still bad connection at the battery itself. To do a voltage drop test you will put your meter in to voltmeter mode. Touch one probe to the positive battery terminal on the battery itself and touch the other probe to the positive cable itself. The ideal situation is that you will not read any voltage. What this does is provide current a second path to go if the connection is poor. If you read anything above 0.3 to 0.5 volts then you will need to clean your battery terminals and cables.
Doug

 

[Mike1992]

Yea good idea, i should unhook the terminals if I plan to kep letting it sat as i've had it for a little while longer. While car is parked I currently get 12.9v off. While car is idling I get 14.3v, then turned car off again and battery is at 13.0v. Seems like things are charging correctly. Battery terminals are new, and i got one hell of a ground wiring kit. I guess Ima just unhook the battery from now on if I wanna let it sit for a few days. Thanks for the help

 

[Doug99RS]

Yeah, 14.+ volts should be sufficient enough to recharge the battery. Good luck and keep us up to date.
Thanks,
Doug

 

[UrMyStlkAl]

Have you tested your altenator? I didn't read through this all the way cuz it was insanly long but just start up your car (after charging it or whatever you gotta do) and while its running pull unplug the battery. If the car still runs, ur batterys bad, if it dies, the alt. is bad.

 

[Mike1992]

Yea I pulled my alt. and had it bench tested last sat. its good to go

 

[Doug99RS]

Originally posted by UrMyStlkAl
I didn't read through this all the way cuz it was insanly long

Feel free to read the insanely long parts before posting. You'll find alot of times that the information is not only valuable but also already stated.
Doug

 

[UrMyStlkAl]

Originally posted by Doug99RS
Feel free to read the insanely long parts before posting. You'll find alot of times that the information is not only valuable but also already stated.
Doug

, I read through it for the most part, but alot of it was scanned and I saw that he had the batt. tested but didn't see where he had the alt. tested so I posted it

 

[Doug99RS]

http://dsmtuners.com/forums/showthread.php?s=&threadid=54846

I forgot to search myself. Here's a tech article that may help as well.
Doug

 

[sedah]

this post doesnt seem to have any replies in a while but its worth a shot Right?
I have a similar problem with this alt. checks out fine. bought a new battery unfortunetely its the taller cheaper one from shucks or something so i had to make a tie down for it .. but that holds it tight.. no arch spots burnt to the hood terminals are clean and fit very tight... i can run the car it starts fine everything works. I let it sit over night (brand new battery lasted 2 days) and its drained dead. i've done the test light circuit test there is a draw and as far as i've come down to its in the radio. no wires look bad. how do i come about and finding out where in this circuit the drain is happening?


Thanks

 

[Doug99RS]

Can you make the draw go away by disconnecting the radio? Are there other systems that share the radio fuse or is the only thing on that circuit? Normally I will start at opposite ends and work towards the middle. In your case this would involve first removing the fuse to make sure the draw is in that circuit. Then you will reinstall the fuse, if the fuse is labeled "radio" I would disconnect the radio and see if the draw goes away. If the draw goes away then either the radio is the source OR the problem is using the radio to complete two circuits (or more). Like.... Wire A is good, wire B is bad but it's not until A&B are plugged in to a common unit that the circuit is completed and your draw returns. So it may not be the radio, just something on the same wiring.
Doug

 

[sedah]

Alright.
i attempted to attach gauge lights to the radio wires before the drain started. the drain occurs after the radios been removed when the gauge light wires were attached it would blow the tail fuse under the hood where as the drain test (test light between negative terminal and wire) only went out when the radio fuse was pulled
so i suppose thats not it

but the drain doesnt stop when the radios been removed and the gauge lights are all removed clean back to stock







91 eagle talon tsi awd

 

[Doug99RS]

So the drain is on the fuse that has the radio on it BUT the drain is still there even with the radio removed. The next step is to disconnect the next wiring harness connector before the radio. Basically you'll have to work your way, from connector to connector, back to the fuse. Eventually you will disconnect a connector and your drain will go away. It's not fun, you'll need a wiring diagram, but it's the only way to do this once you've removed the main things like the radio.
Doug

 

[sedah]

Ah Bummer
I've got my diagrams ready later today when i get up i'll head out n find where its at.
i'll let ya know when i find it or if i find it.
something i've found already
haynes manual diagrams are not for begginers definetely a complicated mess to a begininer

 

[Doug99RS]

I think Haynes manuals are confusing for everyone but the haynes manual people. And the Mitsubishi manuals leave out SOOO much detail on the text aspect. Wiring diagrams are normally pretty good though.
Doug