We have a 2006 Toyota Sienna Mini-van that was new to us when we bought it last October. A few months after we bought the car, we were surprised to discover that it appeared to have a dead battery one morning. Wouldn’t turn over, made no noise, just dead. We blamed it on a possible interior light left on by one of the grandkids, but weren’t sure about this. The car ran fine after a jump and continued to do so for weeks after this. The the problem occurred again with the same ambiguous circumstances. Another jump an no problems again for more than a month. Then it went dead in a parking lot while we were in a store - so was dead after only 20-30 minutes. Unfortunately, a grandkid was in the vehicle running something off the power outlet (a phone?). A jump worked again and no problem for an extended period of time.
This summer we took a road trip from our home in northern Minnesota across North Dakota and Montana to Glacier National Park. On the way across North Dakota we stopped for lunch at a information/rest area in North Dakota. After finishing lunch (20-25 minutes), we found the car “dead” again. An attendant at the rest area gave us a jump and we headed to a Wal-Mart (it was Sunday) in the next larger town. They checked the battery and said it appeared to be fine. They didn’t have the capacity to check the alternator or other electrical related stuff. We continued on to Montana and had no further problems for a few days. Then one morning it failed to have any battery power and we needed a jump from someone in the campground. We headed to a repair shop that handled electrical work about 50 miles away.
The repair shop confirmed that the batter seemed fine, but found the output from the alternator was not as expected when running the car. They recommended replacing the alternator. After replacing the alternator we returned to our trip and things were fine for two days. Then the car was dead again. After a jump we headed for an auto parts store and bought a quick jump unit so that we would no longer need to rely on others and vowed to get the car fixed when we returned home.
On the way home, stopped at a rest area to have lunch and the car “died” again in the few minutes we spent having lunch. The jump starter worked fine and we continued on. We needed another jump later in the trip home, but the pattern of working a couple of days and then failing continued. Since returning home (over a week now), there hasn’t been any problem. The car was used on one long days driving (about 8 hours of total driving) and other wise short trips around town.
The unpredictable nature of this problem and the disappearance of the problem after getting a jump and driving has us stumped. The car acts as though the battery is getting charged after the jump, but at some point loses it all and in some cases this happens in less than 1/2 an hour although we don’t know for sure that the battery was fully charged when we stopped. I suppose it could be barely charged when we stop and in 20 minutes loses what is left. But often times, like now, the battery seems to remain charged for days. In the past it would be okay for weeks.
The car has power seats, power windows, power locks via a key fob, power sliding side doors and a power back hatch door. On the camping trip these power doors were used frequently as we would get things out of the car or put them back in, but that was going on every day and the power would disappear after 2-3 days rather than 20 minutes.
At this point we can’t duplicate the problem at will. We have to wait for it to happen. Then a jump start and driving restores the power for as much as 1 or 2 days, so getting to the repair shop immediately after it happens isn’t very useful. Leaving it at the repair shop for days hoping it will happen while there is also impractical since we really depend on the car.
Any ideas as to what could cause this “strange” problem? We will be taking it in for repair at an automotive electrical repair shop in a few days, but I would like to have some idea of what they can or should be looking for. Thanks for any ideas.