Rep Power: 0

Ok my battery light would come on if it rained a lot been doing it since I bought the car but now problems always went out. Two weeks ago I was driving to work and battery light was still on from the day before I didn't think anything of it. On my way to work lights dim then radio shut off then gauges stopped working. I pulled over I got the car jumped to try TO make it to the auto parts store. after the jump battery light went off so I went to the store and had the battery and alt. Tested both were good but my neg. Terminal was lose. So I thought that was the problem. No problems after that until yesterday can out and started car and battery light was on (no rain). I didn't want to take a chance so I got a new battery after work and tried that. Battery light didn't go out and after it running for a short time battery was low. Any help would be greatly appreciated I don't know where to start.

 
Rep Power: 518

Do you get a loud SCREECH noise sometimes when you start it?
See if the belt is too loose.

 
Rep Power: 0

I had a problem like that a few months ago (minus the rain) with the battery draining etc. For me it turned out to be a relay that was sticking in the on position. I suggest getting a multimeter, turning off the car, doors closed etc, disconnecting the positive terminal and putting the meter between the positive terminal on the battery and the positive cable and see of there is any current draw. If you're getting anything excessive then something is either stuck on or there is a short.

 
Rep Power: 186

Check the voltage at the battery with when the car is on with no load with a multimeter. See if the alternator is actually charging it. It should be somewhere around 14 volts.