2004 Audi A4 battery dying.
 

Hello all, new here so please bear with me. I have a problem with my battery dying if the car isn't driven every couple days. I mean dead dead, even the locks wont engage or any interior lights. We put it on an electric charger overnight, and nothing. So we removed the negative charger cable and it charged in a couple of hours. Got it started, ran it for a bit, turned it off, then back on. I guess my question is, what could be leeching it? Please help. Thank you.

Buy an amp clamp from the auto parts store, and hook it around your battery cable. It will give you an amp reading. for example: 1.2amps
Something like that, you start pulling fuses, one at a time. check the reading, and if it doesnt change, re insert the fuse.

Next, get the car running, and set your multimeter to volts. Put one lead on the positive wire of the alternator, and the other end on the positive battery cable. If you have a number, say 3.4volts, you have a voltage drop between your alternator, and your battery. This will keep the battery from getting the amps it needs to stay charged.

If you go through all the fuses and relays, and dont find a voltage drop, the next easiest thing to do is to take the alternator off and get it bench tested. It could have bad diodes.

If the alternator tests good, and you dont find a voltage drop, or draw from a fuse, then you have a pretty intricate problem. Sometimes it could be something like a security system, or a module problem.

Hope this helps, Connor.