This has not been covered from what I can find but I have a 2015 GMC 1500 SLT and both the 10 & 18 wire are brown. Both wires look to be different shades of brown maybe. I can't tell if they are different shade Browns or the same. But I took a chance and tried it and it worked. But I am concerned that I am wrong. But I looked, checked counted, looked, checked, counted etc. I even disconnected it made sure it went back to fogs turning off when high beams were on. Hooked it back up and the fogs came on with high beams. THOUGHTS???
I will go back and recheck what I know I have already varified. But I do know I am on the right ones. I will look for stripes on the brown ASAP. And post back. In the mean time if you hear do this from anyone else please,let me know. Thx john