Urgent help needed.

Ok guys, to the point here. In a blizzard right now and having some issues. I have went through three napa batteries in two years on my 1994 Turbo Legacy. The recent one is three weeks old. Sometimes when im driving my seatbelt alarm starts chiming and doesnt stop, even with both belts buckled, it still chimes. I go out thismorning to start the car, nothing. Dead battery. So i jump it from my gfs car, let it charge for ten mins or so, then take off to work a half mile away. By the time i get into the parking lot, all my interior lights are very dim and the abs light came on in the dash. I turned on the windshield wipers to try and clear some more snow, and boom the car died right there. Went to crank it back up and barely turned over and then nothing, just a click. Got it jumped again, let it charge with the cables still hooked up to the other vehicle. Checked the voltage with a meter, showed 13.5. Unhooked the cables, the motor raised in rpms slightly and checked the meter again, showed 12.45 volts. Drove it back home, ( all lights, heater, radio off) and pulled in the lot at my apt and shut it off. Then tried to start it back up, and it cranked over fast just like it should. What is going on?? Sorry if i rambled on, but i tried to detail everything as much as i could.

Bad alternator

It does sound like a bad alternator. Also clean all the grounds, check all power cables, make sure the battery you are getting fits the specs of the car.

Ok so i went out again, started up fine. I took it for a drive, but i noticed when i turned on the headlights and the heater the clock light on the radio got really dim, as did the gear indicator on the dash.

Measured the voltage between, the neg post and the engine block and the tranny case, and it showed no voltage.

 

I measured running voltage between neg a pos. posts again, with heater on and headlights on, showed 11.9. With heater and headlights off, showed 12.9 volts.

 

I did notice the negative battery cable clamp had been broken at the bottom, and had been jimmy rigged back together.

 

Before i go throwing parts, is there any other definitive test i can do to rule out either the cable and/or the alternator?

I think you should have at least 13 volts with your headlights on and the engine running. Have someone blip the engine and see if the voltage fluctuates with engine speed.

If you haven't already, check the alternator belt. My brother had a legacy with odd charging behavior and it was from a slightly loose belt that would slip but not all the time. May or may not be your problem but it's easy to check and costs nothing.

Ok so today took the battery out and took it to NAPA to have them charge and check it. Left it for a while, showed back up and they said it was bad, wouldnt hold the charge. This batt was only a month old, bought it february 4th. They warrantied it, got the new one, along with a new 4 ga. negative cable. Installed the new cable and battery, cleaned all connections, tightened, etc.... Cranked and started just fine. voltage showed 12.3 with headlights, heater, and radio on. Showed 13.0 with everything off. I guess its time to swap the alternator? Should i drive to the parts store and have them check it before i swap? And do you have any preferences when it comes to which parts store to use for alternator? Thanks again for all the help.

Rebuilt cheaper...brand new better. With the car off I think battery only suppose to pull 9? Good luck

have them test the new one before you put it in. went through like 3 bad ones before i got a good one.