What the ****? 2 battery, and my alternator is showin a fine voltage. Im not havin any electrical problems in any other area. So whats goin on?

 

same thing happend to me on my t2. got a new battery, turned the key...started. turned off, turned on again...dead. it ended up being a terminal and the battery cables. they are really sensitve...check em out.

 

I already went through all of that, my car ran for about 6 hours with the new battery, so thats why i thought it was the alternator, but its fine. I dont know. Ill go back through it again, its gotta be some kinda connection or ground, because nothing else makes sense.

 

same thing happened to me.. dead battery. alternator was charging so i bought a new battery. next day, DEAD.
turns out, i found out from a friend of mine my reverse lights kicked on in 5th gear! i recently swapped transmissions so i guess the wires running back to the reverse light switch were shorting.. ?
i was going to d/c the whole switch altogether, and find out once and for all.. but my engine exploded :/
but yah.. shorts are a bitch. the wires are so fragile anymore

 

You have a current draw, get a digital multi meter and start pulling fuses.

Check your lights on like the hatch light and dome light as well.

 

How are you testing the alternator? Just showing voltage output is not enough. Take it off and have it tested at an auto parts store. My alternator went bad and still put out the correct voltage but a diode was bad and it fried my new battery.

Also check for current draw when the car is off.

Are you using a MULTI meter? What all have you checked?

 

Could be something as simple as corroded battery posts and connectors. Perhaps a little scrubbing with a wire brush?

Also, check to see if the heavy guage black wire running from the alternator to the main block is connected, and that a similar wire from the mail block to the battery is also intack.

So many times it's the simple things.

Good luck.