2003 Chevrolet Express 3500 Q&A

2003 Chevrolet Express 3500 Question: how can I trouble shoot the coil pack and the electric going to the coil pack.

Meaning how could I check the wiring harness. -
Answer 1
check for spark -
Comment 1
I have no spark I want to know how to check it back to a fuse -
Answer 2
No fire at all on any cylinder? If only one cyl. misfire, swap that coil with another one to see if misfire follows coil. -