You haven't made clear whether you're monitoring the inputs by watching the LED on the input module, or whether you're using the PLC's programming software to monitor the operation of the program.
A couple of questions: Has this system ever worked properly, or are you trying to set it up for the first time? Are you able to monitor the operation of the program? Is the PLC running? Most PLC outputs require their own power. Is there power for your outputs?
In a situation like this, there are two broad possibilities. The first is that the PLC is telling the output to turn on, but the output refuses to cooperate. That implies that the problem lies in the hardware (failed output circuit, blown fuse, no power, miswired, etc).
The other possibility is that the PLC is not commanding the output to turn on. That points to a different set of things to look at, including the program, and, as Ron pointed out, the rest of the conditions that need to be satisfied before the PLC commands the output to turn on. Its possible that, in addition to your joystick, you need some other input device (like a light curtain) to be satisfied before the motor can be alloweed to turn.
We first need to determine which of those two broad possibilities are involved here, then we can look more closely in the proper direction.
I asked the question about whether the system has ever worked properly because it has been my experience that PLC programs don't wear out, but hardware does. Limit switches get bumped out of alignment, photocell lenses get covered with dust, wires break, fuses blow. It has also been my experience that people have a tendency to blame problems on the things that they don't understand very well. The attitude seems to be "I don't know exactly what that PLC does, so it must be what's causing my problem".
