I guess I haven't been keeping up with the models so excuse my stupid question....what is a GMC Sierra Refresh?

 

The ones with the new interior, new front etc on the 2022.5 1500.
2022's prior to the refresh are called '1500 LTD' by GM (and are the same as the 2021's)

 

Try to find the directions of adding oe fog lights. There is a spot behind the glovebox with what seems like a rubber plug but it’s been so long since I’ve done it now that I can’t remember

 

Assuming the 3.0 is the same firewall and stuff bolted to it as the l5p, I just did a 2nd truck like this. There's a rubber tit straight back from the passenger battery sticking out of the big rubber wiring harness that passes into the cab. Cut the end off and run a wire fish down through that hole. It will end up under the pass. dash, but you'll have to remove the black plastic bracket thingamajig there, just imagine where that wire is coming through the firewall and you'll see what plastic thing is in the way. Remove it, and the fish will be right there for you to pull your wire through. I passed an 8awg wire through that tit no problem, probably able to fit a 6awg through, but two wires? Better make it smaller 12awg to fit 2 of 'em through or be prepared to butcher the rubber harness plug.
If you don't need much amperage on that wire you're running, you could also tap the pass. fuse block for something under 10A and use a ground point under the dash.

 

Look into “Upfitter” switches. There is a couple threads on here.. the thread will discuss I think:

9L7 Upfitter Kit, surveillance Switch

Recently was issued a 2021 2500HD Custom with the gas burner for a work truck. First thing I ordered was the 9L7 upfitter switch kit (has new knee bolster with the 5 AUX switches, and all related wiring and fuse block). Over on the GM Upfitter site I grabbed the latest Body Electrical PDF...

www.duramaxforum.com

 

I installed hide away strobes on my truck yesterday (21 Silverado 3L Duramax). I found the easiest way to access the fire wall was to remove the air filter box, and then place the coolant reservoir down in that area. Once the coolant reservoir is out of the way you can see the firewall pass through and you just need to snip the nipple on it and then you can run wires through it. Also, the cab side has foam insulation right behind the pedals so you’ll need to cut or move the foam over to find your wires.