hi, my 51 plate brava reverse lights have gone off so i bought new bulbs and replaced them, still no joy so i'm assuming my reverse light switch has gone off, i know this switch is attached to the gear box, but i don't know where is it underneath the gearbox or attackable in the bonnet, there is a wire coming from the gearbox in the bonnet is the switch or is it the speedo wire or sommit, don't wanna pull anything unless i'm sure, it the 1.2sx 2001, thank you in advance.