99 Suburban wont crank

7.4L 454
Wont crank.
Repalced Battery & Starter.
Just starts to turn engine then just clicks. Battery gauge on dash goes from 11 amps down to near 2 lights go dark... nothing.
any ideas??
Can't even jump start it:banghead:

Make sure both ends of both battery cables are clean and secure.

//2000CAYukon

Turns out, there is/was a short in the ground wire coming from my brake controller. The wire melted while continual cranking. I cut the wire and it starts & runs great. Now I have to trace the wire and try to find where it was contacting live wires.