how to replace the reverse light swith in zafira?

I hope this helps:
Reversing light switch - testing, removal and refitting
Testing
The reversing light circuit is controlled by a plunger-type switch that is screwed into the top of the transmission, towards the front of the housing. If a fault develops in the circuit, first ensure that the circuit fuse has not blown.
To test the switch, disconnect the wiring connector. Use a multirneter (set to the resistance function) or a battery-and-bulb test circuit to check that there is continuity between the switch terminals only when reverse gear is selected. If this is not the case, and there are no obvious breaks or other
damage to the wires, the switch is faulty, and must be renewed.
Removal
To improve access to the switch, remove the battery and mounting plate
Disconnect the wiring connector, ther unscrew the switch and remove it from the transmission casing along with its sealing washer.
Refitting
Fit a new sealing washer to the switch, ther screw it back into position in the top of the transmission housing and tighten it to the specified torque. Reconnect the wiring connector, then refit the battery (where removed) and test the operation of the circuit

koter002
March 2009