Hi can anyone tell me where the reverse light switch on the ZF autobox is please? I have checked the rest of the circuit.

I thought that the reverse light switch was built into the isolation gearbox switch on the 300TDi/ZF Disco ...

The D1s switch is in a similar position, to what's shown above, left hand side of the box where the selector rod is but of course looks a bit different from the Td5s. Remove the U clamp and pull the switch from the gearbox, it's recommended a new replacement O ring is used when refitting.

The reverse light switch is an integral part of the start inhibit switch.