2004 Sebring sedan, 2.7 with 130k. The first issue I had was an erratic shift and a lurch at idle. I didn't have a lot of time to mess with it, so I took it to the dealer for diag. They said it was a bad alternator. On the way home from the dealer, the battery light came on. The battery is about 5 months old. The car sat for 3-4 weeks. I started to mess with it again a couple of days ago, and the battery was stone dead. I put an alternator on it anyway (which was the worst alternator job I think I've ever done), and attempted to charge the battery with a charger. When connecting to the underhood posts, it would spark like it was connected backwards. When connecting to the battery, it didn't act like that. I removed the battery and attempted to charge it overnight, but it didn't take a charge. I took it today, and the parts store said it was a bad battery. When I tried to reconnect the new battery, it sparked like crazy when I tried to hook up the negative post. Did I have a short that was the cause of the battery/alternator dying, or did I do something after the fact? Where should I start to look?

 

You may very well have a short. There will be a little sparking normally because there are things that draw current even with everything off, such as the clock and the remote key receiver. There's also a little surge when you connect as the computers power up and the airbag capacitors charge up. Normal current draw when things settle down with everything off should be in the range of 50 milliamps or less (0.050 amperes). If it's much more than that you've got a short. You'll need to trace it down by pulling fuses one at a time until you locate the bad circuit, then trace that circuit and the devices on it to find the short.

 

This is not like the normal slight spark you get when attaching the battery. This is more like welding, like it was under the hood when I tried to charge the battery using underhood posts. So I suppose I'm off to try it the hard way.

 

UPDATE: I found that the reman alternator had a piece of plastic missing on the B+ stud, which was allowing the tab on the wire end to contact the alternator case and short out. I returned the alternator and put another reman on. I checked the output at 13.6 and thought all was well. That was this weekend. My girlfriend drove it to work and back Monday and Tuesday, about 20 miles round trip each day. Today it died on her way to work. She got it stopped in a parking lot, and it wouldn't even try to start. The battery acted completely dead, as though disconnected.

I got it towed, and when I got home I put the battery charger on it on 75amp jump start, and it started right up. I disconnected the charger and let it run about 10 minutes. I turned it off and restarted it off the battery with no problem. I restarted it and let it idle for another 20 minutes, verified I was getting good voltage at the alternator and at the power and ground jump studs under the hood. I was getting 13.5-6 at both places with it running. As it idled a little longer, the rpms started to fluxuate, and I put the multimeter back on and could watch the voltage drop. It got down to 12 volts under the same conditions before I shut it off. Am I likely losing voltage due to a bad reman alternator, or did I fry the PCM or something when the B+ was shorting on the alternator case? Would you suspect the PCM is getting hot?

 

Doubtful that a short from the B+ to the alternator case would have any effect on the PCM. It's not like it's dragging that current through the PCM.
If your battery was stone dead again, and you quick-started the car with a big jump, your battery might still be basically dead. The alternator won't put out a charge if the battery is dead. Try slow charging it overnight and see if it's better in the morning.

 

I should mention that the battery was replaced (under warranty) after the B+ was shorting to the alternator case. The battery is less than a week old. The car will start and run just fine on its own. The alternator is putting out...until it decides not to anymore. I need to determine if I got a bad reman out of the box, or if I've got something else causing it to quit charging (or go to reduced charging). The only two times I can prove it quit charging is when it was driven for 20 minutes and died, and then when I got it home and saw it on the multimeter at idle after 20 minutes, when the idle started to fluxuate. The voltage was dropping before my eyes. I shut it off, waited just a couple of minutes, and restarted the car. Then the voltage was back to 13.6 immediately.

 

Bump. Anyone got any ideas?