Symptoms that are not described well in other posts including Bill's posts.

Ignition in on position (not start) I get clicking in passenger area. Sounds like glove box, but could be footwell area. Car wont start, get all kinds of DIC errors sometimes. 1518 error, etc. Eventually, I can turn to on position and when it does not click and DIC says Corvette without complaining, it will then start fine. Runs fine once started.

I've read a lot of posts and have a dozen things to check that would take me all weekend. Of course I'll do them all if needed, but would like to isolate it a bit more. Nobody seems to mention the clicking even before trying to start. The seems to eliminate the starter or solenoid all together to me.

I get the P1518 code. Charge system failure, low voltage, etc.

I recently did some mods and had the neg battery disconnected, the intake off, moved right coolant tang to get to right shock, put a LS2 TB on my LS6 with the adapter kit.
Neg battery is tight, but I will take that off and redo.

I've read there is a cyl head ground wire up in the area by the intake and firewall. Possible I crimped it somehow.

I've read there is a ground by the coolant tank, but according to your Bills Ground pics, its really by the battery.

If a fuse were bad (no_start doc), would it be intermittent, or just not ever work?

When it does crank, it cranks hard so I doubt its the battery, but I could stop into Advanceauto to check. Just another time eater.

I did have the starter/solenoid replaced 6 months ago with a non crank problem. But again, even without turning key to start, I notice clicking and DIC flashing and or dimly lit.

 

Have the battery load tested, that would be the first thing to do. You can't really do anything else until you are sure the battery is okay. Start with the easy and cheap things.

 

I did the Bill Curry ignition switch refurbish and I no longer have problems. Wow!