2G Open circuit?

[Speed94]

I've been through two batteries already in the last year and I just replaced the alternator the other day. The new battery was bought 2 days ago and is now completely dead.

My question is how do I find the open circuit in the car or rather, is there an easy way to find it. I ran a scan with a snap on scanner at a shop and it didn't throw any codes despite the Check Engine light being on, but he cleared it anyway.

I have no idea whats killing the battery but I need some suggestions. When you jump the car, it will stay on but that's only because the alternator is powering everything, once you shut the car down, nothing lights up not even dimly.

Someone help me out here. Thanks

 

[Defiant]

Disconnect the battery and hook up a test light between the terminal and the battery. Start pulling fuses until the light goes out. Once you've found the one that turns out the light, trace it down to the short.

 

[Speed94]

so heres another problem....when I disconnect the negative cable from the battery and connect a test light to the positive terminal and the other end to the negative cable(not connected to the battery) the light doesn't light up, but when you connect to the battery post directly it lights up. And when you touch to a new ground somewhere in the engine bay bay it doesn't light up either. The battery now reads 10 volts from 2 days ago, but I think its because the ground is bad.....when I test volts from the battery terminals alone with the car off, it reads around 12v....its below freezing here. Anyone have any suggestions? Thanks

 

[steve]

Originally posted by Speed94
so heres another problem....when I disconnect the negative cable from the battery and connect a test light to the positive terminal and the other end to the negative cable(not connected to the battery) the light doesn't light up, but when you connect to the battery post directly it lights up. And when you touch to a new ground somewhere in the engine bay bay it doesn't light up either. The battery now reads 10 volts from 2 days ago, but I think its because the ground is bad.....when I test volts from the battery terminals alone with the car off, it reads around 12v....its below freezing here. Anyone have any suggestions? Thanks

With the negative battery terminal disconnected you don't have a complete circuit, so no current flows. Try connecting the light between the negative battery post and the disconnected cable. That will complete the circuit.

Keep in mind the the ECU and the radio draw some current all the time to keep their settings backed up.

Steve

 

[Speed94]

So I connected the test light between the negative cable and the negative post and the light came on (there's a draw somewhere). I start pulling fuses one by one and by the time I get to the last fuse the light is still on I checked the fuses under the hood and in the driver kick, now I'm completly stumped. I am going to run a new ground wire tomorrow from the alternator directly to the battery even though I am getting continuity between the two.

Anyone have any suggestions? Thanks

 

[tsunari]

So it dies while just sitting around? Or perhaps does the alternator/charging system need to be tested . . .?

 

[luv2rallye]

You obviously have a partial short somewhere in the car between the +12V and ground (negative terminal) which is draining the battery even when the car is turned off. With everything turned off (but battery still connected) take your voltmeter and start measuring voltages everywhere there is supposed to be +12 volts (like at the fuses, switches, etc). Keep in mind some circuits/fuses don't have voltage until a switch/relay is activated while others do. The circuit where the partial short is will read something other than 0 or +12V (like between 1 and 10 volts). If there was no short, all non-zero voltages should be almost (electrical loads reduce voltage slightly) exactly the same as the battery voltage.

Do your headlights work with the car off? When you turn the key to just on, do you get any dashboard lights?