For months I have been plagued with dead battery issues. All the normal mechanical suspects had been eliminated but still after only 4 hours after shutdown the drain was enough to discharge the battery. Overnight it would completely discharge and require a slow charge to bring back the battery. I started to explore all the electrical systems by elimination. As you can imagine many hours were involved in this process. I finally found a partial solution by disconnecting the twin 30A fuses which controlled the after shutdown functions such as headlights, radio system, auto door locks etc. I believe the fuses are marked "28" on the legend. As long as I pulled this fuse, located under the hood, after shutdown the truck would start after sitting for days. I just plugged it back in before start up and no problem. I continued to try to isolate which "after shutdown" component was not powering down. After another month of trial and error I had my vehicle in for a normal tune up by my mechanic. Not a dealership as they were absolutely useless in assisting me. This was a young mechanic in our small town. I told him since they would have my truck overnight he would have to pop the fuses I mentioned or it would not start in the morning. He just said "interesting", do you want me to check it out. Not having much faith I said OK but don't spend more than 2 hours labour searching. Then I asked him if he drank beer! He said yes to which I replied "if you can solve that damm problem I'll buy you a case of beer". We agreed and I left my truck for service. I'm sure you have already guessed the results. I hope he enjoys that case of beer! It turned out to be the compass and temperature sensor which was not powering down. I know many others have been dealing with similar problems so I am hoping this helps you out. I now need to locate a replacement part so if anyone knows where I can locate one your help would be appreciated. Good luck and happy motoring.