I am wiring in foglights, OEM ones, and running a 30amp relay direct to the battery. I am getting signal to allow power to the relay via the stock lowbeam wiring, and I need to know something about the switch I am going to use.

The switch will be between the signal to turn the relay on, and the lowbeam wiring. It only supports 12amp (tiny inconspicuous switch). Do I need to get something that will support the 30amp? Or would that only be if I had it going inline with the battery/foglight itself?

I am unsure of the requirements for amperage as far as the switch side goes, when using a relay versus just tapping in direct.

 

You will be ok with that switch and relay. The switch is just to turn the relay thats it. The 30 amp is for the wiring between the battery and lights. You will be good.