Hi all. I have had an interesting morning. I woke up to a dead battery. I pulled a battery out of another car and hooked it up and immediately heard a light hissing sound coming from what appeared to be the right side of the engine. You can also hear a faint hum from inside the car as well. All this with no keys in the ingnition. I'm wondering if that is what made my battery go dead. It onlymakes the sound when the battery is hooked up, if I disconnect the battery, all noise stops.I also did a boneheaded thing that I'm hoping didn't cause this problem. WHen I pulled the battery from the other car, I didn't pay attention to the fact that the poles on the battery are reversed. DOH!!! So I ended up crossing the terminals. I arced it for about a half second before I realized what I had done. What do you think? yeah I know, I'm an idoit! LOL I was able to start the car with no problems once I was on the right posts, but whatever is continuing to run under the hood is still there when I turn it off. Any help would be greatly appreciated.

Steve

 

Try to isolate to the part making the noise and describe it a little better if you can.

 

OK, I went out and bought a new battery, hooked it up and no more hissing sound. Something seems however to still dishcarge the battery slowly overnight. I went out and started the engine 24 hours after putting the new battery in and it started but the battery seemed a little weak. I'm wondering if I created the problem when I inadvertently crossed the +/- posts for a half second when diagnosing the problem originally. Alhtough when I went out friday morning when All this started, it was the coldest morning we've had in awhile. Either way, somethings up. Any help would be great!!

Thanks,
Steve

 

You need to test for a parasitic draw with an Amp meter.

 

OK, I think I may have found my problem with the battery draw. I pulled the negative cable and checked the battery with a meter. zero, no draw that I coould find. NOW THEN..... I think my problem may have stemmed from the fact that I spilled a little gas in my trunk and had been leaving my trunk lid cracked overnight about 6 inches to air it out. I turned the light off, but I guess it still created a draw somehow. Since I stopped doing that, no more dead battery. Either that or it seems to have fixed itself! LOL

Thanks again for the help!