Starting,reverse lights,rear wiper

Megane II 1.4 16v, won't start using brake pedal, will with clutch. Reverse lights are not working nor is the rear wiper when reverse is selected. Three wires going to switch on the gearbox, yellow has power going in, brown and white I think are feeds coming out for reverse lights and wiper.

Do I need a new reverse switch on the gearbox to cure my non starting problem. Can get ignition on using the brake pedal but will not crank.

Thanks.