I am at my wits end with my aux battery. Trying to figure out the cause of the problem. Definitely there isn't a draw somewhere. Or so I thought. But my knowledge base on this is limited.

Wiring is not standard by a long shot. 

The problem from last season is the battery seems to run down way too quickly. I have multiple things powered by it, but I thought when the car runs, the alternator would charge it through the main battery. (There is an isolator between for when it's off.)

So, the battery, which I bought last summer, was dead. So my plan was to charge it, then try to figure out which connection has the draw when everything is off (top guesses are radio and truckfridge). Before hand, I disco once everything from the aux battery. I test it and it was like a 5v. I plug the van into an electricity source (home outlet) then plug my charger into the outlet inside the van, and then clips to positive and negative. I leave it overnight.

I go out this morning, disconnect the charger and test. 12.26v with some fluctuations. I leave it. I come back 20 min later, and test it again and it reads 11.14v. This, I think, is telling me the battery is not holding a charge.  This was a new battery when I bought it. How could I kill it so badly, if I did? I bought this battery new because I wanted to take the old previous battery out of the equation. But do I have such a draw that I'm killing batteries so quickly?

I'd like to get more info before I buy a new battery. The current one is just a basic from Car Quest. My next one may be the expensive deep cycle.

Can some patient people try to tell me what I'm doing wrong, and maybe walk me through some next steps.

Any other info needed on this, let me know

Jeremy, '87 Westy

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