so my alt has been checked o.k. at three different places and my batt has also. when the batt is fully charged and i turn on my car the batt guage inside reads at 12 volts. for about a week it will stay this way getting a very little bit lower until one day when it just drains completely when i turn the car on. i was thinking the wires from my alt arent working or some wire goin to my batt isnt working because when the car is on it should be between 15 and 18 volts but instead its at the batt voltage. any ideas? there cant be a short because on one day less than a week after the batt was fully charged it drains completely on that day.

 

is the radio clock on? like does it never shut off even when the car is off?

turning the key on and off to check the battery + a leak somewhere would possibly do it.

why would your volt meter read 15-18 with the car on?? I've never heard of this.. umm

 

clock is off, as matter of fact i took out the stereo. my friends 87 T/A reads around 16 volts when the car is on and mine is 12 volts.

 

can anyone give me an idea as to what my problem is?
like i said, everyone elses 3rd gen f-body reads around 16 volts when their car is on but mine doesnt. instead im reading the batt voltage which is 12 volts as if the alt isnt charging but i got it checked out at a couple different places and its good.

 

ok well i had a similar problem in my firebird..for awhile it was draining my battery like that until it caught fire 2 times becuase my wires going to the battery terminal were corroded. You should try replacing your battery wires the black and red..you can score those pretty cheap...also in my alternator experience sometimes if youve had a failed alternator thats killed your battery one or more times the battery itself can go bad.

 

Well as said prior, the radio things is always the first thing to check as it is very common problem with GM factory radios. I have replaced thousands of those radios, literally! Now does your center counsel compartment have a light in it?? This may cause it also, if neither of these. Remove each fuse from the fuse box ONE at a time. This is easier to do with a friend. What you want to do it remove the ground wire from the battery, does it spark as you touch it back on the Battery?? If so, you have a draw somewhere. This is where the removing of ONE fuse at a time starts. Start by removing the Accesory fuse. now touch the ground to the battery again, does it still spark? If yes, move on to another fuse, and try touching the ground to the battery again, still sparks? continue on with this till there is no spark anymore. once you have no spark at the ground, that is the curcit that is causing your draw. This will at least tell you where to start looking anyway. HTHs

 

all my light bulbs are out of the car and i have checked for a draw before and i found nothing. still any ideas? where can i get the factory battery terminal cables? ive looked at some places and they only have the batt cable and my positive cable has a wire going to the alternator.

 

Call your local GM dealership, and see if they can help you, or make new ones yourself. Buy some 1 guage and some 6 guage wire and fix her up. If your going to make your own, make sure to take a measurement of what you need. Positve and Negative cables use 1 guage wire, for the wire to teh alternator use 6 guage wire. The places that checked your battery?? Did they just do a Volt test, or an actual Draw test( Load test)??

 

they did a volt test and a draw test. ya im gonna stop by a GM dealer and see what they can get me for cables. i really hope thats my problem cause ive had this problem for a while.

also while im asking questions...my temp guage works but doesnt read the temp and my cooling fans never turn on. what could that be? im pretty sure the fans work (not 100% sure) but they have never turned on since i bought the car.

 

I will need more info on the car to answer those types of questions. Make, year, and engine.

 

87 chevy camaro IROC Z 350 TPI dual cooling fans...

 

There are 3 senors that go into your coolant passages, one on the Driverside head. this usually controls the guage if I remember right, and one on the Pass. head also, that controls the one fan. Also another on the front of the Base of the intake, this is the temp sensor for the ECM. Someone please correct me if I got them messed up.

You may even have some bad Fan relays too though.

 

lol well as i said a few posts above i had the prob with the terminals/wires on the batt in my bird and same thing is happening to my 91 blazer..keeps draining and needing to be jumped (brand spanking new alternator) and its a fairly new battery. I think you should honestly replace the battery get a nice fresh one, plus the new cables as i suggested. Im gonna replace mine tonight. Yes GM is where you should get your cables they should have them. I dont think hes draining cause of a fan relay im leaning more towards the bad wires idea.

 

It doesn't sound like your alternator is charging the battery. Get a digital voltmeter and measure the voltage across the battery with the car off, accessories on, and engine on. The engine on should register about 16, IIRC. That's from memory, so I could be wrong about the specific voltage. Just note that engine on will be higher than engine off. If it's not, check the wiring for your alternator.

FWIW, I had a similar problem at one time, everything was hunky dorey, except it would drain over a few days. I had a bad starter solenoid and it was draining my battery. The solenoid died from some jump start attempts.

 

i have checked it with a voltmeter and it reads just under 12 volts with the car running and 12 volts with the car off. im thinking i have a bad connection with my alt wire to my batt also but it looks fine to me. i will try getting new cables and see what happens from there.

now about my cooling fans. what is the part that send the temp information to the computer called? i think i need a new one of those. where can i get one and around how much does it cost?

 

Dude! Did you say under 12 volts when runnning?? Yes you did. The alternator should be making more like13.5 to 14 Volts when running. Your alternator is gonzo, maybe a connection, but I'm guessing the ALT. is shot! If you have some extra cash, I would replace the battery too, if not then charge yours up really good. Sometimes a old battery can kill a new ALT. I totally misunderstood your first post here. The alternator is most likely done. I would still check the connections, just to make sure.

 

the thing is, ive had my alt checked at three diff places and when they checked it, it was reading between 14 and 16 volts and they said it was good. just when the car is one theres a problem.

 

Well check the cable going from the alt to the battery. Now I beleive that alt has 4 wires on it?? One goes to the Battery (6-8 guage Blk/Red ) Then a (16 guage Red) to the fused link to the starter solinoid. A brown wire to the guage cluster, and finally a either WHT/TAN wire or TAN/WHT Which goes to the fuse block. Check all of these for a bad connection and see how you make out. HTH's?

 

I found this post helpful.

I have this same problem. I did once try to jump my car mutiple times then after that i noticed my battery dying every couple of days.

My question is that would this drain make the negative battery cable spark when reconnecting it to the battery?

Also would corroded battery cables make the negative spark?

Thanks

 

Yes.No.

There's alot of voodoo and black magic type stuff in people's answers. Alot of lack of basic understanding of electricity and how to use test equipment.

Understand that the thing in your dash that waves up and down and has a picture of a battery on it and goes from 8 to 18 is NOT test equipment. It's part of a trim pacakge. About all it's good for is noticing "Hey it's like WWWAAAYYYY different today than yesterday" and getting something fixed. Just because your car's "volmeter" say 12 and somebody else's says 16 doesn't mean that theirs is working great and yours isn't. Now if yours said 16 yesterday and says 12 today, than that's useful; that's about all it's good for.

The first thing you have to do is to determine if the alt is charging when it's on your car.

Go to Radio Shack and get yourself a digital multimeter, you can get an entirely adequate one for about $20. Put it in the "DC Volts" position, and measure the battery voltage with the battery fully charged and the car not running. Then start the car and measure it again. It should be higher with the car running. Specifically, it should be around 12.5V with the car off, and around 13.8-14.4 with it running. If it doesn't go up when the car is running, then the alt is not working, even though the alt itself may be good. The thing that will most often cause it to do this is a bad "Choke" light bulb. (Don't ask.) Turn the engine off, let it die, then turn the key to On with the engine not running; the "Choke" light should come on. If it doesn't, put in a new bulb. Repeat the voltage tests.

Come back and tell us what you found. If it still has trouble, next we'll use the meter to find a drain.

 

Thanks.

I have been having this problem for a while.

I have a new battery a new alt and checked everywhere else for a drain.

So im down to the cables and starter and im replacing both of them.

 

Cables and starters won't cause this.

You're wasting your time and your money.

Enjoy!!!

 

Hello Mike,

Check your e-mail!!!!!

 

This seems to be what happned to be. Kept trying to jump the car and now after that the battery dies in a few days.

How do you know it coudlnt' be my starter solenoid. Like I said I have replace everything else and checked everything. Those are the only 2 things i haven't done.

 

Because I understand in minute detail how electricity works in general, and specifically how the charging and starting systems in a car work. It's not black magic to me like it is to some people.

FWIW I'm a mathemetician and physicist by education and an electronic engineer by trade, but mostly just an idiot that nobody ever believes the first time I tell them something. They just have to go find out that I'm right for themselves the hard way. But that's OK, I'm used to that; I have a wife and teenage kids, so I get it from all sides. I'm getting comfortable with the fact that I'm really just damn near the stupidest person that's ever hit the face of the planet.

 

Ahh good old RB's word. A very wise man he is. He has saved my cars **** many a day now. Anyway, back to the topic at hand. If your solenoid was bad, i dont think youd have power at all to your car. I may be wrong, but my car was dead as NAILS, i replaced the solenoid and all was well again. So if you can see your radio, your gauges light up and all that good stuff, i think your starter solenoid is fine. thats just my thought. dont quote me on that, though.

If you get your battery fully charged, what happens when you unplug the negative battery terminal and tap it to the battery post?

 

If you have access to a DVOM check the parasitic draw on the battery 50 milli amps is the max it should have (.050 amps) to do this disconnect the batt. cable put the meter on amps put one end on the cable and one on the batt terminal (make sure you have nothing on like the dome light with the door open or a under hood light or you will get a bad reading) if it is under .050 amps your problem is in the alternator, battery or wiring to the alt. if it is over .050 amps something is on, to narrow it down start pulling fuses till the draw goes away then you now what circuit it is in

 

When I do tap it spark fly everywhere.

RB--Im not going aganist anything you say. But I have been dealing with this problem for a year and now and this a haulted me from driving my car alot.

Its just that those are the only 2 things i haven't done.

Like I said Alt is new. Battery is new.

The car gradually does in a few days.

I have disconnected my stereo, I have done the fuse test.

Everything checked out fine.

Also I can tell you this.

I stored my car before I was going to school last novermber 2002.

I have a digital lighting cap for my stereo which reads volts. It would stay on all the time reading like 12volts or something. Then In february 2003. I tried to start the car literally like 200 times. I had bad spark plugs. Replaced them. Car started. But then I Noticed lighting cap woudlnt' stay for longer than like an hour. So I know there is a short some where so that is the only thing I can think of.

As i said. new alt and new battery.

Thanks

 

lol !!! Where's the smilie with the "I'm with stupid" sign when ya need it??

 

There is your most likely cause. You have a bad ground somewhere. When this happened to me, it was the ground strap that connected the passenger cylinder head to the firewall.

 

What excalty is a ground strap?

more info please

Thanks

 

the ground strap is a large wire, or a group of woven wires, rather, that goes from the rear of the engine to the firewall. At least that is how it was attached on mine. The strap is about 1/2" thick behind the pass. cylinder head. Feel back there, you cant miss it. Also, to either of you with this problem, just to be on the safe side, go over all the other grounds on the engine. Do a search, or look in a book, for all the ground locations. For me, my strap was the problem. It was corroded.

 

I think you guys may be onto something...I'd check the above. It won't charge properly w/a missing ground strap. :werd:

Post what you find out....

 

Yup, i have a buddy with a 92 Z28, had the same problem. He replaced his starter, solenoid, battery, all the wires, you name it. Only to find it was that $2 piece of wire behind the head.

 

anyone have a pic of this. Also how hard is this piece to replace?

 

LMFAO

My car's battery has a drain. I traced it to the headlight control module. It's a firebird, though.

 

I have a thought about the spraking when you reconnect the negative.

If you have a hoodlight. Woudln't that make it spark everytime because the hoodlight is looking for power?

 

The power for that comes off one of the fusible links at the starter solenoid and should have an in-line 4 AMP fuse on it depending on the year and model. Your purple wire from the starter solenoid goes to the P/N switch on an automatic and the clutch start switch on a manual. Check it for a short to ground.

 

It sparks because you have a bad ground somewhere.

 

So in theory if i get a spark meaing i have a bad ground....that would that rule out the possibly of my starter draining my battery?

I just want to know that spark means bad ground somewhere?

 

i have this same problem now.i gutted my computer in the dash and have a really nice high amp chrome alternator...custom wound to throw like 140 amps...and i have a bad battery draw somewhere...now where it gets interesting...when the car has been off for about 2 minutes the alternator puts out a very high pitched whine....?????? i will check the alternator with another sooner or later but in the meantime i have a good looking battery cut-off key switch....works for me plus a lil insurance