The line that you are using for power, whether you are tapping into the ecu or the fog light power wire at the headlight switch, just make sure the in line fuse is closer to the source you are tapping for power. If that's confusing to you let me know.

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2018 Ram 2500 6.7L Cummins 68RFE
19k miles -Bright White/Black - Big Horn Sport - Crew Cab Short Bed
2013 X5 35D (CEO's) - Born on 5/17/2013 -
82k miles - Alpine White/Cinnamon Brown/Premium Pkg, Sport Activity/Premium Pkg and Sound/20" Style 214/Running Boards