George B
¯\_(ツ)_/¯
I just went out and started my truck. when I turn the fog lights on with it running in park and the headlight switch in auto it turns the fog and running lights on. I can understand having a diode in the right direction so the fogs come on with the running lights because if it's backwards the fogs would not come on with the headlights or park lights. maybe the diode is redundant. would require some testing.There must be a need or their instructions wouldn’t tell you to install it in a certain direction. And like Wes said, it’s probably so the fogs work without the park lights. I tried jumping the BCM trigger wires but I was going from the headlight relay trigger to the fog lights relay trigger wires and it didn’t work right. I tried it with and without a diode.


