drewguere

I have an 83 Mustang GT with an original 4cyl, but a 5.0 swapped in. I can jumpstart it, and it will start and run fine, but as soon as I shut off the motor, the battery is dead. Im not sure what it is, I figuerd it could be the alternator, but if that was shot, wouldn't it not run right, or shut off while running?

Its also a brand new battery.

Ecstasy

your alterntaor doesnt start charging to 1500 rpms, it doesnt charge at idle. alternator could be going bad, id change it out anyways if you have the money, because its the only way to really eliminate that issue. you have a new battery so you can eliminate that, new alternator so you can eliminate that(if you get a new one)

Hung Like a Stang

true. but just because its a new battery, doesn't mean its good.

That battery could have been sitting for a year or more and could be completely sulfated by now and will never take a charge.

I'd get both the alternator and the battery tested so you know.

drewguere

OK, Im at college, so I only get to work on it briefly during the weekends, but next weekend Ill replace the alt, and Ill throw in a different battery. We'll see what happens.

Its so frusterating because Ive been working like a madman over the past month to get it going right, and I haven't had very much time to work on it, and just this little thing keeps me from driving it anywhere.

ZachW04Stang

I got a battery from walmart and had the same problem. After I went through 2 more batteries from walmart the 3rd one finally held a charge.

Hung Like a Stang

yeah, batteries sit too long, paste falls off the plates, and battery is sulfates, and is no good. High possibility that is the case.

AdderMk2

i'd be willing to bet that you have a bad battery terminal. I had a similar situtation with my probe. Terminal was no good and getting poor contact, but when i'd hook up the jumpers it would start fine... even just connecting the cable itself allowed the car to start... b/c it completed the connection