Question

How do I determine if the switch is bad or if the pump is bad on a c2 cassette toilet. I have already checked the 3 amp fuse and it was broken so I replace it. The toilet will not flush.

Answer

If the 3 amp fuse was broken then it it almost certain that the pump is faulty. The pump is beneath the toilet roll holder. You will need to undo a screw to remove the pump and then cut the electrical wire and remove the water hose. Strip back the wire and connect the pump directly across the battery to check operation.
If you purchase a new pump it comes complete with electrical connections and heat-shrink sleeving so that you can connect the new pump and fit the sleeving to seal from the water. Make sure you slide the sleeving onto the wire before making the electrical connection.