My Fiat Freemont's start button doesn't work

Assuming the vehicle is starting and stopping correctly via the start button, you could be looking at anything from a faulty component in the switch’s lighting circuit, to a bigger problem with the car’s body computer. An auto electrician should be your first stop to get it sorted.

But until you can book in to an auto sparkie, try this trick at home. Disconnect the battery and leave it disconnected for an hour or so. Then reconnect it and see if the problem has gone away. Sometimes, a body computer needs a reset, and disconnecting the battery is the equivalent of Alt-Ctrl-Delete, or turning a computer off at the wall and switching it back on.