Electrical Problem Pls help

[Levi Walkup]

Hey everyone, I have a 1999 gmc sierra 1500 4x4 sle, The past month or two ive been having some problems with my truck. Sometimes when I go to start my truck, itll act as if there is no power to the vehicle at all, wont even make the rapid clicking noise it usually makes when the battery is dead. I didnt have a fuse panel cover or box cover and Id go through the creek and get mud and water in my fuse box all the time, and most the time my truck would stay on after I turned the key to off, and the horn would stay on. The last time I went out the horn stayed on and then eventually turned off and now no longer works, Im thinking that maybe the horn relay or fuse is drawing power the entire time and slowly killing my battery. I just got a brand new Duralast Gold battery and all new battery terminal bolts on saturday and it was dead this morning reading below 9v, so theres obviously a power drain somewhere. If anyone has had this problem or knows anyone who could help that would be great!

[sefiroxx]

Use a amp meter in line between one of the battery cables and a battery cable.

Then start pulling fuses to see which fuse causes the amp draw to drop.