Hello

I'm getting ready to retrofit my OEM headlights in the next month or so. But I want to do some reading on tapping sources in a car.

From what I've read here, It seems people have to tap the fog lights or side markers for any Halos or DRLs they wan to add to their builds but I want to have a general understanding of the process. Any online sources you guys can recommend? I have a 2013 MCS if that helps. Everything I find here doesn't have a how-to tap and I want to know the details.

Thanks
G