I got the bus started yesterday, and still feels like a fluke - was able to remove (unplug) vandalock units to remove unneeded beeping (hatch, rear door). Progress!
What is happening is when the batteries are connected, instantly the bus warning lights come on but solid, not flashing. There is an audible alarm from driver side where batt and electrics live.
The alarm stops when key is turned to IGN and the bus starts, which it did first pop. As a workaround I can install a knife blade switch at batt terminal, but wanted to find out more info so I can do it once and right.
Any thoughts or suggestions?