Where is the reversing light switch on a Renault laguna?

The reversing light switch on a Renault laguna is in much the same as on many other cars. Basically it links to the gearbox or the gear lever, so that when the gear lever is at the reverse position it engages the switch. On the laguna it is on the gearbox near to the left hand end (from the drivers view). You must remove the left front wheel to see it more clearly and possibly the plastic under-engine plastic shield.

The switch is normally open, and shorts out when you engage reverse, so you can test it with an ohm meter.