If i remember correctly, the switch is only a 2 pin so if you wanted to be 100% sure before you got a new switch, short out the 2 pins and switch on the ignition.

Reverse lights should illuminate if the switch is the problem.

Another test you can do to ensure that the switch is at fault and not something internal to the gearbox is to select reverse and check for continuity across the 2 pins on the switch.

There should be little to no resistance.

Mark.
