I have the same issue, same truck. 2000 1500, 5.9 single cab short bed sport 2wd. I'm thinkin
I'm overlooking a bad ground somewhere
my psychotic alarm that grounds out all the time is fryin em
possibly harnesses behind gauge cluster r wiggling loose?
Dude, if u figure sumthin out, plz share, I even used a pcm out of an 01 w a 5.2 for a while (w an ever present p0031 [upstream O2], p0037 [downstream O2], n p1495 [leak detection pump] while using it tho)