Drove the car home about 6 weeks ago. Removed the battery and had it fully charged by Interstate. Dropped the subframe. Painted it and motor mounts. Replaced everything that involved rubber and all wheel bearings. Put the subframe back in. Tested Bat and it is good so installed it. Replaced spark plugs, wires & ignition coil on the LS1. Turned ignition key with unwarranted confidence.
Got interior cabin lights, key warning, weak headlights, and horn but nothing else. No dash gauges, no fuel pump, no ABS pump, no starter click. Nada.
The remote battery is only grounded to the chassis in the trunk. In reading the results of a search, someone suggested adding a second battery grounding point as a failsafe.
I am thinking that in painting the subframe I might have effectively insulated the engine from ground. Tough to do considering how many grounding cables there are.
I also want to check the positive cable. Not clear if the Bat+ cable running under the car is in some kind of tunnel or is exposed.
My search disclosed that the Bat+ cable goes to a bus bolt on the left firewall. Surprisingly, I could find no pictures of this bus bolt so I'm assuming it is pretty obvious. From what I read, that bus bolt is cabled to one on the right firewall that operates as the main power feed.