something draining my battery

[rightaway]

Something in my car is drawing all the power from my battery. if i let the car sit 2 or more days, the battery dies. I had this problem for a while. I cant find what's killing the battery.

so i tried this. I got a new optima red top and put it in. put the positive terminal on. keep the negative terminal unhook, hook a volt meter between the negative on the battery and the terminal and was showing 14.5 volts. all doors where closed and key were out of the car. pulled all the fuses under the hook and under the dash and it still stayed the same.

so i borrowed my friends blue point multimeter.to try to run another test. i see, ohm,dcv,v~,a~ and dca. which one is the so i try next?

and is there a way to check the alt. to make sure that is not the problem?

 

[coguy1234]

Get a test light. Turn everything off take the battery hot side loose. Connect the test light between the hot side of the battery and the hot side battery cable. Does the light come on? If so start taking out the fuses one at a time untill you find what circuit is causeing the drain.

 

[dieseltech]

sigh, bad idea coguy. Our cars, any cars for that matter that has electrical components that require a memory will have some sort of parasitic draw. This is what you need to do. Take the bluepoint meter and Hook the positive lead into the DCA socket (dca stands for Direct Current Amps). Unhook your negative cable and take a reading. In school they tought us no more than 50mA of draw. More than likely you will find you have 1 amp or more of draw. Unhook your fuses outside first. If none of them fix your amperage draw problem unhook your meter and move inside the car. This part will require two people. You don't want to have the door open with the meter hooked up or you will blow the fuse inside the meter, and they're not cheap (6 bucks or so a piece). Pull fuses one at a time and have your friend let you know when the amp draw drops to the normal range. On a side note i have seen cars draw 3-4 amps when the meter is first connected and then drop to a normal range, I have not however done this test to a dsm. Thankfully i haven't had the need to do this test. You may find its something simple, like a glove box light or something like that

 

[91 Turbo Mitsu]

Get a test light. Turn everything off take the battery hot side loose. Connect the test light between the hot side of the battery and the hot side battery cable. Does the light come on? If so start taking out the fuses one at a time untill you find what circuit is causeing the drain.

I have worked on thousands of cars)am an ASE certified mechanic) and this is the way we all find electrical draws. Obviosly the computer is going to draw some juice but the test light is usually very dim because the draw from the ecm is minimal. As you unhook fuses one at a time check the test light after each one to see how brite the light is.When you find the fuse or fuses that make the light go dim or go out,find out what they go to and find your draw. I have seen glove box lights,trunk lights and even obscure interior lights that stay on and cause the drain on the battery. If you need more help pm me and we can talk over the phone. I"ll be glad to help as much as I can. keep us posted and good luck. Travis

 

[dieseltech]

Not to argue too much. I have used the test light too. My point is that not in all cases is it trustworthy. We even learned the test light method in college but the instructor informed us of the possibility of inaccuricies, that is why i favor the Dvom method over the test light. I will use a test light in any vehicle that is not computer controlled, other than that I break out the DVOM. Is it over kill? Being 100% sure that you have found your problem is never overkill.

 

[rightaway]

i tried to test out the system. i tested it using my multimeter. first i tested it out by using the DCA. come up zero. than i MA test. come up zero again, but if i went up to the V~ on
200m, and up with 5. pulled all fuses. nothing changed. any other ideas?

 

[b00st3d]

$10 says it the alternator. The regulator in the alternator to be more specific. Pull it off and go have it tested.

Do this...

While sitting in the car, turn off the key and listen for the "click" after the key is off, normally is heard 1-3 seconds after the key is switched to the off position. If you here that click it's most likely goin to be the alt. IF you hear no click, that main relay in the center console is probably the problem.

 

[rightaway]

can i test the alt. while its in the car? it didnt click today but i think i might heard it before. where is the main fuse. under where the radio in or like where the cup hold is?



there is a vibration/humming noise coming from under the hood, near the firewall, when the car is off just stitting there.no keys in the car. any idea what that could be?

 

[rightaway]

i test the alt. while it was in the car. 12.2volts with the car off. 14.5 with the car running. took off the positive cable, car ran fine. so does that mean that the alt. is good?

 

[dieseltech]

he means for you to unhook the positive wire to the alternator and do your parasitic draw test