So I think I stumbled onto something this evening. I have an air compressor that runs off a car's cigarette lighter outlet. To power the Prius' outlet, the car must be powered up. So this evening, while checking the tires, I powered up the car to [IG ON]. This is done by hitting the (POWER) button twice without your foot on the brake. This brings all the electrical systems online but does not engage the hybrid systems or start the ICE. I did the driver's side first, passed the compressor through the front seats, shut the driver's door and did the passenger side. Due to the cord plugged in, I had to open the front passenger's door. When all was said and done, I reached in through the passenger's door and pressed the (POWER) button to shut the car down. I shut the front passenger's door and walked into the garage. Realizing that I usually keep the compressor in the cargo area, turned around and walked back towards the Prius. The lights were on. You see, since the Prius doesn't have stock Daytime Running Lamps, I keep my headlights ON at all times. They come on when I power up the car and turn off when I open the driver's door. So why were they still on after I powered down? I experimented: 1) Open the passenger door, power on the car to [IG ON], power the car off, lock the doors if you want, shut the passenger door. The lights stayed on. 2) Open the driver's door, power the car to [IG ON], power the car off. . . The lights immediately shut off. 3) Get in the driver's seat, shut the door, power the car to [IG ON], power the car off, open the driver's door. The lights immediately go off. This says to me that the lights are triggered by the driver's door and only the driver's door. Of course, the occasion is rare that you will not exit the car through the driver's door, but there are those times, few and far between, when you will find yourself reaching through the passenger's door to power down or parking close the on the driver's side and crawling across. For me, I used the same compressor last year to inflate my wife and my bike tires on the passenger side. Later that evening, my neighbor knocked on the door to let me know that the Prius was beeping and such; the 12v battery was drained. Would someone go confirm that this is in fact a way in which a Prius owner might accidentally drain their 12v battery? I failed to check the dome light. If you don't have your headlights on, see if the dome light stays on.
Yes, that is how it works. Auot off only operates with the drivers door. This feature causing a dead 12v has been reported on several ocassions here on Priuschat
And if you don't close the driver's or other door fully, the dome light will stay on all night. That won't help the SOC of the 12V battery. Harry
<div class='quotetop'>QUOTE(seasalsa @ Sep 30 2007, 07:34 PM) [snapback]519608[/snapback]</div> Goes to show that I don't pay much attention. Actually, I know there have been reports of drained battery, but I wasn't completely sure that there was a definitive explanation.
How I killed my 12v: Had it in IG ON with fan on and didn't hear it + neighbor mowing lawn + bright sun shining on dash = didn't see dash lights or hear long beep when trying to lock car and left it ON! Lesson learned? Don't use ignition on unless you are sitting in the drivers seat the entire time.
