Advisory: Emergency Exits and Parking brake on INTL
Just to let everyone know, later model buses have lots of safety features built in. One such feature is that if there is a fault in any of the emergency exits or door sensors, the air brakes (parking brakes) will not release until said fault is remedied.
This happened to me over the weekend - I pulled the wiring harness out, starting the bus after each disconnect. When I tried to move it later with all the harnesses out, the parking brake would not disengage. I remedied it fairly easily.
However, I took it to the shop yesterday, parked it in the driveway (blocking it) shut it down and they wouldn't release again. Stuck there for two hours tracing which wire came loose (a hidden connector).
Other safety features include a non-start of the engine in certain circumstances, but I have only heard, not experienced those.