I have a short in my truck that takes about 3 days to run down the battery. I have put a 12 volt lamp between the negative battery post and negative terminal and pulled all fuses under the dash and under the hood, one by one, and the lamp stays lit. What would cause this slow drain discharge?

 

I know about one other thing that can cause a drain and won't show up with the regular "pulling of the fuses" -- the alternator. Maybe you can disconnect where the fusable link attaches to the starter relay and see if the drain goes away? Also, you may want to try totally disconnecting your starter and see if the drain goes away. For such a slow drain though, I wouldn't really suspect the alternator or the starter -- wouldn't those cause larger, faster drains? My current (bad) alternator draws about 3.2amps constantly, if my measurements are correct. I'm replacing it soon.