Howdy fellow SL's. Installing a digital voltmeter with 2 usb connectors to my 2018 RTL. Got it installed(middle blank in switch cluster) and wires snaked through the spyder under world and want to connect into a keyed power source. I found the fog light circuit and not sure which color is positive (black or white/yellow) or any better suggestions for tie-in up front?

Thanks for any light you might shed.