Fog lights on w/ High Beams, New GM trucks
Works just like on the last couple gen trucks. New 2020 Silverado Will see how much it helps. Last Chebby, 2016 model, it was night and day difference (pun intended, lol). Well not quite, but...
Forum Discussion
01tundra wrote:Grit dog wrote:
I question how full manual control of the fogs is possible with the Boostauto or DIY diode mod.
IIRC, Boostauto doesn't claim the ability to turn off the fogs when high beams are activated and it doesn't make sense that it would be possible. Last 2 trucks I did, the fogs were automaticlaly on with the high beams. Just like this one.
Regardless, if you have your brights on, it's for more light and the more the better!
I haven't really given it much thought, but I can confirm that the Boostauto kit does indeed allow you to turn the fogs on/off with high beams on via the factory fog light switch.
range of control of the fog lights on/off with high beam on may depend on the year of the truck.
On my 2015.5 GMC 2500HD denali the diode mod including the boost auto creates a logic OR function, not a logic AND function. Fog lights on if the fog light switch is on OR if the high beams are on. I have the full set of truck wiring schematics for the upfitters and the BCM control for the lights is done via logic states, not relays etc. and the boost auto (and as far as I could determine the ONLY way) to do the fog light control with high beam via logic functions basically "tricks" the BCM to think the fog light switch is on and the high beams are off.
Other years may have different logic for the BCM and may allow the fog light switch to turn the fog lights off with the high beams on with the diode mod installed.
