S80 backup light wont work

backup lights are turned on by the transmission range selector switch on the transmission.

The "back-up Reverse light switch I believe is incorporated in the gear shift selector Dash or console mounted?

their is a relay of the reverse lights thats prob. bad is located in fuse box under the hood

You will need to either replace or adjust your backup switch, it is located on the transmission next to the shifter. Hope this helps, thank you for using FixYa!

the reverse back up lights usually light up when the car is in reverse gear.., however get the wiring checked as you already have checked the fuse and bulbs.

bad ground to wire. shorted wire or bad plug

Buy a auto repair manual for your respective truck, or go to the Nissan dealer and ask a tech to show you where the actuator switch is located, and replace that switch. That is the only thing left to replace. That should fix it. Also you could use an Ohm meter to check the switch to see if it is bad. Also check for a broken wire when you remove the actuator switch.
Good Luck!

There is a switch on the steering colum that works the backup lights

check for the connector socket, and or remove the socket and clean the teeth and fix it back

Yes it screws in on right side of tramission and you will need a 7/8 inch deep socket to remove it. You may be able to clean the old one once it is removed. There is a little ball thatgets dirty and may you can get by with cleaning it. Good Luck. Ed