2019 Ram won't start after disconnecting battery

[knelso4]

Have had a problem with UConnect rebooting every 205 seconds. Decided to try reset. Disconnected negative terminal for 20 minutes. After reconnecting, truck won't start. No solenoid click. Warnings for air bag, power steering, antilock brake, stability control. There was more arcing / sparking when the cable was touched to the post than I expected, but I assume that was just because everything was de-energized. I hope I didn't toast something.

Suggestions?

 

[stevj]

There's a battery condition sensor at the negative terminal.
Did you disconnect that sensor before you removed the negative terminal?

Steve