Check for voltage drain?

[alemmons]

Okay, I am trying to see if I have a short or something causing me to have a constant drain from my battery. I havd the battery tested at Autozone and they said it was good. The battery is at least 2-3 years old. Any time I leave the vehicle parked for a day or two at most, the battery is low enough that I can't start it.

I read somewhere that I could use a multimeter between a battery post and the wire to check it out. Could someone give me a link or explain what I need to check. Thanks.

Aaron

 

[Dirt]

you can use a multi meter for this by disconnecting the neg. battery cable and inserting the leads of your meter inline with your meter on amps. i'm sure some one will post a link or you can try a search in oem tech using parasidic draw as your search key words. basically hook the meter up and see what the draw is it should be very close to 0. if you have a whole number you have an excessive draw. you can look and see if any accessories are on (dome lights, glovebox light, are the doors shut all the way?) Or you can pull fuses till the draw goes away that's the circuit your draw is on.

 

[Pappy]

If you use a volt meter you'll read 12 volts but it won't tell you if it's a big draw or tiny draw on the batt. Disconnect the neg or pos and leave the other cable connected. Clip a test wire to the empty bat post and clip a test wire to the disconnected cable, touch the wires to a small 12 volt bulb (about the size of a small dome light bulb) if the test bulb lights up you have a big draw. Make sure that when you do the test the key is off and doors are shut. In doing this you are creating a big series circuit, all the current in the vehicle has to pass through the little test light. When the bulb lights up start pulling fuzes, one at a time, until the test light goes out. Find out which components run on that circuit and check them. With the test light connected nothing in the vehicle will work, except maybe radio memory, and strange things will happen. Pay no attention to the wierd stuff and concentrate on making the light go out.