SOLVED: Front end rattle over bumps/manhole covers/pot holes?

Has anyone ever experienced a rattle from (seemingly) the front end focused on the middle/drivers side "behind the dash" of a 3rd gen truck when driving over manhole covers/bumps in the road?

It only really happens at low speeds, and sounds like something (a shield or plate?) is rattling on a panel somewhere. I've been chasing this for a few days now, and have removed the skid plate, fuel tank skid plate, and even the rubber shields in the front fender wells. I've even climbed under the truck trying to tighten my cat heat shields to no avail.

I've spent (actual) hours both under and above the truck looking in the engine bay triple checking every single thing that could be rattling/bouncing in the engine bay.

I've also ripped apart the entire drivers side under-dash/steering column area to check for any potential noise makers and found nothing.

I'm going to try zip tying the wiring harness on the passenger side as a last resort, I'm wondering if that's allowing the harness to flex enough to shake on that clip and rattle but I really don't think that's it and figured I'd put a feeler thread out.

I'm going to try and get video footage of the noise today.
Any ideas would be greatly appreciated; this rattle is going to be the end of me...

I just recently installed a Magnuson supercharger and I'm not sure if the noise was there before the install, mostly because I've been driving the truck around with the music off to listen for any stray/weird noises from the S/C. So far, I've put 400+ miles on the supercharger with zero issues.

 

HAH! Solved my own problem. I have a Genesis Dual Battery kit/tray installed in this truck. Turns out I must have gotten lucky on the installation of the battery tray, because the noise didn't happen until after I removed/installed the tray for the supercharger install.

If you are familiar with the Genesis dual battery kit, you would know that on the 2018+ trucks (with LED headlights) you need to trim the fuse box and mount the fuse box backwards. Well, it turns out, when there are 100 lbs of batteries mounted in the tray, the tray "sags" and is in close proximity to the old fuse box mount... There was obvious powder/paint transfer that was going on when I pulled the tray out, and I connected the dots and put a bit of felt tape on the tray and the fuse box mount, and the noise is no longer present! I am 100% sure it was the fuse box mount, as I took the tray in/out of the truck twice today, the first time I simply took it out, and put it back in which greatly reduced the noise (but it was still there on certain very harsh pot holes), then brought it back home and knew I was getting closer to the culprit.... more intense staring at the battery tray/fuse box mount/general battery area led me to see what I was missing right before my eyes, that transfer of powder/wear marks.

The noise transmits so darn well, it's like the wiring harness on the passenger side people kept having problems with -- the fuse box mount is very similar, sheet metal that is perched in the air. If you tap on the mount itself, you can definitely hear what would feel like that problem.

On the directions, on page 5, you can see the fuse box leg/mount I'm talking about: https://drive.google.com/file/d/15hg_4X1HjdUagdSK7NjMN1phK9BJugrB/view

Anyway, problem solved! I hope in the future, if someone runs into a rattle after installing their Genesis dual battery kit, this will help them.