Rear Contactor

I do not have a backup light that works
I do not have 2 wires coming out of the switch.
I'm looking for a schematic or know these two are connected or son and they spend

I tested the conctacteur

On Rear engaged 1.20ohm
Reverse not engaged 1.20ohm

switch HS

is it necessary to drain the box replace the switch?

thank you