The battery died a couple months back, we were at a stoplight and everything in the dash as well as radio shut off and coming to a stop resulted in the battery dying and shutting off the car. We took it to the shop and they replaced the battery, Napa Legend. Everything seemed fine for a while. About a week ago it was only starting after the 2nd try, it was very cold so I dismissed it. Then the other day as we were planning a big trip, car wouldn’t start. We figured the battery had froze, so we jumped it with my car and everything seemed fine. An hour into the trip and again everything in the dash/radio shut off, so we pulled into a gas station and let it run, eventually the alternator charged the battery, everything came back on, battery light shut off. We drove home instead of continuing our trip. The car was fine the whole drive back. So today we took it to the shop and he says it “might” be the alternator. They tested it though and it came back fine. Battery tested as well, just fine. So, after doing some research I found out about the electric load detector. It controls the voltage regulator inside the alternator because it uses a dual mode charging system. How would I diagnose this? I also need to check wire connections from the battery but the only way to get to anything like the starter where the positive terminal leads to is to remove the intake manifold.. such a pain. I don’t think it’s the alternator. If it was, we would’ve been stranded as the battery would not have recharged or made it the whole hour drive back. One more thing, I have a diagnostics code reader, and we got a p1166. That has to do with the oxygen sensor I guess. Would that be able to drain the battery or is this highly unrelated? Last week I didn’t have any codes show up, but if the wiring is bad it might have erased stored codes. I’m very new to fixing my own vehicles and any advice would be appreciated thanks for reading.