My battery was dead the other day in my truck. After charging it and starting it, I noticed later on in the day thatmy compass light and heater fan were running without even the key in the ignition. Now the battery is dead again? Is there a reset on the computer that causes the lights and fan to come on? or are they killin gthe battery?

 

I would think that the accessories running would cause the battery to go dead. Next question is why are they on? I'd check grounds at the battery and between engine and frame. Have any work done on it lately? Anything added to it as an accessory that had to be wired in? Ik've check wiring schematic and don't see anything common.