Hey guys, hoping to get some help with my sub tank switch. (2008 series 4 GU ST 3.0)

I had the dash apart to install some cable for aux power running to the back of the car and installed a new uhf and gone to put everything back together and the sub tank switch has stopped working.
Does the sub tank switch light on the actual switch and the light in the dash only come on when there is fuel in the sub tank or should these LED's illuminate when you press the button even when the tank is empty?
I've considered replacing the switch but Nissan want over $100 for it. Narva do an OE style switch Ive considered replacing it with but the original has 6 wires and the Narva one only 4 wires. Can't seem to find a wiring diagram for the switch so I can identify what the wires are. Ive already had the ground cable disconnected, checked all fuses. there is 12V supply right to the switch, but when you press the button, no lights come on and nothing happens.

any guidance would be appreciated. thanks.