I have been performing this mod since whenever fog lights started going off when you turned on the high beams.
I would like to say that I was the originator of this mod as I used to sell diodes with instructions at local car and truck meets, swap meets and over the counter at my parts counterman job.
It's good to see someone started posting this online - it's probably one of the coolest mods you can do to a Chevy Truck.