Originally posted by Stocky: I had exactly the same problem, and it turned out to be a short in the overhead dome light. Pop out assembly, disconnect and see if problem disappears.
Good luck,
Marvin Stockman
Funny, mine too... except mine was so bad the assembly melted.
When checking for current draw, make sure that you have under hood light turned off(set something on the switch to turn it off). This could give you a false reading. Same is true for other courtesy lights.
Good Luck Dan
96 SE 2.5 V-6
89 Silverado 4 x 4 with snow plow no rust
Turns out that it was the dome light. Unplugged with a new battery installed, I'm still testing at 12.3-12.4 volts, even after allowing to sit overnight.