Did you check the switch in the overhead console that controls the lights. There are 3 settings: Off, Door and ON. Sounds like it's in the ON position.
I just did a quick internet search to get that pic. I apologize if it's not the correct piece I was talking about. I just know my truck does it daily and when I was laying under it putting my new suspension on and had my buddy open the door to check something, that was where the noise came from.
Lay under your truck and look at the inside of the frame under the drivers door. You can't miss it. And I've been under my truck when it primed. It's quite obvious.
It's your fuel pump priming. It's mounted on the inside of the frame right under the driver's door. Chevy set it up so it primes when you open the door so there is no chance for fuel starvation on startup and or you don't have to wait for it to prime when you turn the key. Definitely an odd setup.
Yeah. These are 29 inch tires in the front right now. Still have the stock 31 on the back. Doing 24s all the way around so I'm gonna end up clearancing the inner fenders some. I just ordered a 2 piece drive shaft conversion yesterday because I'm rubbing on the cross member on large bumps and I still want to go down another inch in back.
I just recently did this upgrade. Bought a used overhead console with homelink built in off eBay for around 50 bucks. Came with everything I needed except it had the sunroof and rear slider switches. So I used my console and swapped the harness parts for the homelink. Then I ordered The correct trim plate for 20 bucks. So at 70 bucks it was definitely worth it.