JonAllen356

Great! I wasn't sure if it was going to be possible. I ordered the diodes and will give it a try next week. Should have plenty of attempts at it since the cheapest thing on Amazon was a 100 pack...

Any chance you took pictures and have the diagram that shows where those connections are? Do the fogs turn off when you switch to high beams? Does the on/off button still work for the fogs even though they come on automatically with the DRL and low-beams? Trying to figure this thing out. There's a clear way to in another post to do this, but it means the fogs are automatically on with the high-beams, which I do not want.

The thread's been dormant for a couple years, but why not revive it and ask a question that I haven't seen yet... Is there a configuration that would automatically put fogs on while the low beams are active but turn them off when high beams are active? Could this be done and also preserve the ability to turn them on or off using the manual button? I like the additional low light of the fogs, particularly how they light up the immediate road while I'm making a turn. I often turn them on manually, but would prefer to have them turn on automatically. However, I don't want them on while the high-beams are active because I drive in states where that is illegal. So the 10-18 and 10-22 mods don't work because they pair the fogs up with the highs (if I'm understanding correctly). I did find a thread from a guy named Coby7 that said he accomplished it by "adding diodes between H4 and K2 to C2 ( Cathode at C2 of course ) of connector 4 of the underhood fuse block" but he didn't post any pictures or a diagram for where those connections are. It is found at: I drive a 2018 GMC Sierra 1500 Texas Edition

I had the same problem in my 2018 Sierra. Couldn’t find a clear solution online, so I took it into the dealership. They said it was some kind of short in the steering wheel controls. I didn’t quite understand how that could be it, but it was under warranty and they replaced the entire steering wheel. That was a week ago and it is working perfectly now. That isn’t to say a new steering wheel will fix your issue, but it looks like it can be caused by an electrical short a bunch of different places in the system. So take it to a qualified mechanic and let them figure out where it is. I just wouldn’t want people buying new touchscreens, HMIs, steering wheels, or whatever throwing darts at the board until something hits based on what worked for someone else.