...doesn't sound normal, ......my guess is the motors are still turning. Since there are a number relays and swithes it's hard to tell right off what the root cause it.
...First, the easiest thing to do is try manually pressing the limit switch(s), ...maybe the h/l door isn't retracting completely to 'make' that switch thus not turning the motor off. If that doesn't do it, ...there's a number of things that could be going on. I'd unplug the h/l motor(s) to at least verify that that is what's making the noise (and also to prevent burning out the motor). At this point, it would be a good time to start familiarizing yourself with the details of how the system operates, ...and have a copy of the RS wiring diagram on hand, ..and go from there.