Re: 7 pin on off on switch
Depends on the lights you're using and the run of wire to power them if you need a relay.
I don't think you've wired the switch correctly either.
2 should be connected to the coil of the relay / light positive. 1 should be connected to 12v positive. 3 to a positive from the reverse lights. 7 as you have it but also to battery negative.
Depending on how you wish to have your lights indicate depends on how you wire them. I have 2 connected to 6 and dash lights connected to 4.
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