Hi there and thank you.
Car: 2002 Nissan Xterra XE 6 Cyl 3.3L
Original issue: Battery started draining overnight/after several hours after having it in the shop for other repairs such as radiator/water pump/intake manifold etc. It doesn't happen all the time, but I would say 90% of the time. They replaced the battery with a new one at the time.
Steps to resolve: Shop first said I had the wrong size battery and replaced it. Then, when that one died, they said it was the cables or connections going to the battery, so they put a temporary cap on the negative lead. Then, they just said "You probably need a new battery!" and left me out to dry. I replaced the connectors that meet the battery posts but the issue still persists. I also tried a completely different brand new battery and it was drained within a day or so.
Other information:
The problem is that most of the time my battery will be completely dead when I try to start my Xterra after it sits a while. I have to jump it with one of those jumper packs I bought almost every morning, and sometimes when I go out for lunch. Other times however, like this morning, it started right up. Most the time though, it is dead. I tried a new battery and the same thing happened. I had the alternator replaced a year ago. I'm fairly certain nothing is pulling a lot of power either when the car is off as this started after the shop and nothing has really changed since then.
Any ideas?
Thanks!