84 5.0 battery being drained. help?

[thalt20]

Something is draining my battery big time. The alternator is brand new and so is the battery. I was told that it could be a hot wire that is getting constant flow even when the car is off. I just hooked up a CD player in it so maybe its a wire in there. Does anyone know where I should look??

 

[90stang5speed]

if this started after the stereo install I would think that the stereo is a posible cause. one way to check that is to take a multimeter, disconect your pos cable from the bat. set the multimeter to amps. place the red lead of the meter on the bat. place the black lead on the pos cable. with everything off (even the hood light) the meter should read less than .2 amps. any thing more than that is considered a paracitic drain. Have a buddy pull fuses (starting with the stereo fuse) until you see the reading drop on the meter. That would be the circut with the draw. I found a defective stereo causing the bat to go dead on a friends car. hope that helps.
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[Mustang5L5]

You need a multimeter that can measure amps in DC current. Some meters can only handle milliamps of DC since the current flows through the meter. Usually the more expensive meters can do 10A DC or better.

My suggestion if you don't have a proper meter...pull the radio fuse and see if problem goes away

 

[dagenham]

First of all how long does it take to drain the battery?? A day, a week?
If you dont have a multi meter you can just use a test light.
I had a burned out taillight bulb actually give me a dead short and drained a brand new battery overnight.

 

[Stever89]

If you dont have a multi meter you can just use a test light.

Exactly. The beauty of the lamp is you don't need a meter, and it's much easier to see than a display or needle.

Turn off the ignition. Take the key out. Turn everything off, lights, stereo, etc. Shut the doors, trunk.

Take a 12v lamp in a socket with two wires attached. Any 12V light bulb will work, you just need it in a socket with the wires.

Unhook the hot side of the battery and put the bulb in series with the + post on the battery and the + cable (connect one wire from the 12v socket to the + post and the other to the + cable.)

The lamp should not be lit. If everything's off, there should not be enough current draw to illuminate it (you may see a very dim glow, if you do, no big deal). If it's draining big time like you say, it'll be lit up pretty brightly.

If you have long enough wires, you can run the bulb down to where you can watch it while you pull fuses. Use longer lengths of wire jumpers as needed NOTE: When you open the door, the dome light will come on and so will your test light. Take the dome lamp out, and any other interior lamp.

Now, as you pull fuses one at a time, the light will go out when you pull the one for the circuit that's causing the drain.

 

[ID89GT]

Hmm never heard of the test light method, ill have to try that out some time