[gazunni]

Check for blown fuses. It has been posted that if you pull the main 40a fuse and replace it sometimes solves the problem.

Often the switch will get corroded inside. When you press the switch can you here the parking brake motor making any sound?

You can also back off the adjusting nuts on the parking brake cable at the back so that you can at least ride again. Make sure you carry some blocks and leave it in gear so it doesn’t roll away.