no power to coil pack

scan for codes and check all fuses under hood. check connections on coils as well. start there.

I checked all fuses all good all good one of my starter relay has only power on one side here is one for you if you use dexcool in your chevy get it out it out it will eat you gaskets trust me [BENJAMIN ]

then it's a fuse box problem if no power check your larger fuses under hood and what you say about dex cool is not true