Ever since I did the cam and headers install about 3 months ago my battery keeps dying. I thought it was the bettery first. The battery was 5 years old so I replaced it with a new one and it still dies within 2 days. I ran the car and pulled the alternator plug to see if it was working and it seems to be working, the engine sped up and slowed back down when I plugged it back in. It seemed to run alot smoother with the Alt unplugged, I dont know if that means anything. I also stuck a screw driver to the back of the alt and it pulled it to but the magnetic force didnt feel very strong. After I charged it, I made sure no lights were on, even the one in the middle console. My main ? is how can I test the battery to see if something is slowly pulling a charge? Or do you guys think it would be more of a bad ground or bad alternator? Thanks.
Right now I charged the battery again and ran it for 10 minutes, shut it off and made sure it was still charged, and unhooked both terminals to see if the battery will hold a charge. I will hook it back up in about 2-3 days. It is a new battery, its an Energizer brand but I guess it could still be bad.

 

Get a voltmeter on the back positive connection on the Alt when its running. Should read like 14 volts or something like that. If its under not around there then chances are the alt is dead.

 

I still could use a little help on this guys. I had the alternator bench tested and it passed all tests. I got a good voltmeter and took off the positive battery cable and hooked the leads from the voltmeter to the postive cable and the positive terminal. Well on the
200ma setting it read a steady .2 - .3ma. Correct me if Im wrong but isnt this in the desired range? Maybe the short fixed itself for now.
I just want to know if .2 - .3 is okay. Thanks.

 

Man you and I have the same problem. Also mine is right after a cam swap. Took my alternator and battery and they both passed testing.

 

Same cam too? Wow. Hopefully someone can help us both out but right now I just need to know if .2-.3ma current draw is okay.

 

I don't know what the current should be but what's the voltage across the battery terminals with the car running? That's how I've always checked for a bad alternator.

 

yeah if you find you issue let me know. Hopefully its the same issue.

 

I didnt check myself but it passed all 3 tests at the parts store.

 

Okay I went and measured current draw with just one of those tiny rearview mirror lights on and it read 6.8ma so Im thinking .2ma is within the desired range and should not kill a battery in 2-4 days. Im thinking my problem has cured itself for the time being. Im going to clean all my connections and grounds tomorrow and leave the battery hooked up and keep a close eye on it.

Oh yeah, the .2ma current draw must be the PCM keeping memory. Whos with me?

 

Your alternator can be charging but have bad diodes that will draw current when everything is off, such as leaving a light on. Try unhooking the alt and then check it the next day. You can also take one end of the battery cable off, Jump a test light from the cable to the post you took the cable off of. if there is any draw the test light will be lit up. Now start removing fuses one at a time until the light goes out..Then that is where your short is. Also you can do this with the alt. remove the hot cable and see if the light goes out. if is does then your diodes are draining your battery. Time for a new alt....

 

When I bought my Camaro the stereo harness was hacked, I rewired it to the best of my abilities, turns out the prev owner had wired a +12v feed from the lighter thats always on and got put into the mix and was making the ground not work correctly and creating a draw, Once I found it, it was fixed. It sucked for a long time having a draw like that.

 

I did that with a test light and it didnt light up. If you read my posts I also did it with a voltmeter and only got .2ma. Still asking if that is acceptable current draw.

 

.2ma is dick all in reality. Its probably memory for the pcm and radio.

Hooking up a test light inbetween the negative terminal and battery will be useless depending on the test light, some light up with the smallest amount of current and they wont go out until EVERY fuse is pulled.

With the car running, whats the VOLTAGE reading at the terminal at the back of the alt?

 

i had this problem for quite some time and even after replacing a battery.

the battery would read say 12.5 volts and every 7 seconds it would drop .01 volts

12.5, 12.49, 12.48 etc.

turns out it was a bad battery from autozone. i exchanged it a couple years later under warrenty after figuring it was just my car alarm (which i later removed and it still drained bad)

now it doesn't do it anymore with the new battery.

 

I dont think its the battery because this problem killed my old battery and I just got a new one thinking the battery was the problem. I will run some of those tests later today. Thanks.

 

You are right, thats why I said the light would be lit up not a low glow.Even some car alarms will pull very low current..If you know how to do this method it works, anyway has worked for me everytime...

 

Or you can do it the right way and hook up a ammeter inbetween your battery and negative cable, And start pulling fuses until the draw is gone, I test light isnt going to give you accurate results.

 

Okay I went and checked a few things. The battery with the car off was a little more than 12 volts and with the car running it was at 14.6 volts. The alternator also read 14.6 volts. I checked the drain before I hooked the battery up and it was still at .2ma. Im just going to keep checking the voltage on the battery every 4 hours or so and see if it drops.
I think the problem went away somehow. I cleaned a few grounds also but that was after. Thanks for the help.

 

Well from 6:00 P.M. yesterday up until 10:00 A.M today it stayed right at 12.2-12.3 volts.
Guess it fixed itself. Weird.

 

When I performed draw test on vehicles, I always looked for less than .025-.030mA reading on my meter or 1/4 of the reserve capacity of the battery. Meaning an RC of 100, I would want no more than .025mA (my meter reading) or 25mA. A reading of .2mA would be 200mA on my meter and would be considered a large draw. Enough to kill the battery in 2 days. If you are still getting .2mA reading, I would think you still have a draw. Like said in a previous post, pull fuses or relays to see if the reading drops. Do you have any aftermarket equipment installed in the vehilce? If so, I would check those first.