I'm thinking the "Timed load" from the timer would need to be hot for functions to run. Unless the switch is getting power from somewhere else (CC system, manual run switch in eq. room, or whatever), I doubt the switch would be the problem. I'm guessing it's the timer or a wire touching somewhere where it shouldn't. Trace the "Timed load" wire from the timer to the switch. Disconnect it and see if the bay stops. If so, your timer is most likely bad.
I am assuming the timer is a Dixmor. If it is something else, all bets are off.