Idiot lights all flashing sometimes, along with the radio screen?

I have unplugged and checked the connections to the computer. Everything looks brand new and spotless

I'm in Vegas, so corrosion is rarely an issue in the desert Southwest

I may have a clue to a connection possibly being loose. Can sometimes duplicate the electrical glitch by rapidly pressing the brake pedal while at a stop, causing the truck to lurch, but even the violent bucking will only cause the dash lights to come on maybe 20% of the time or less, and like always they're off within a few seconds

Seeing I'm unable to narrow down the issue, I can't even determine if it's safe to drive the vehicle or not without risking more damage

I previously inspected the connections to the computer, and all looked shiny and new. I'm in Vegas, so it's very rare to see any type of corrosion

I'm not sure if I should tell my customer she can even drive her truck, without possibly doing more damage

I looked everywhere for the g201 ground, but was unable to find it. I removed both lower dash panels - not sure if the instrument cluster has to be removed to gain access or not, or if I have to disassemble the duct work behind the center console

This is the best image I could find for location, but it still didn't help

Would that be between the glove box and the door, or the glove box and the center of the dash. And will the evaporator be blocking my access?

Thanks

I need to get hands on the ground location. The electrical problem is very intermittent, and when everything drops out it's only for a few seconds, and then right back on

So you could test everything and it would show good, because as the truck sits there running nothing goes wrong - only shows up intermittently while driving

I might give it one more shot before having to give up

Have not touched the dash cluster. I believe column has to be dropped, airbag disconnected, and possibly dash cap removed to gain access - and was really trying to avoid all that

I will try moving stuff around with the vehicle running, haven't thought of that

UPDATE

Removed lower dash panels, one side to the other. Proceeded to reach up and wiggled all wiring harnesses, could not duplicate issue

Also could not find anywhere ground 201, even stuck my inspection camera and to all the little spaces and nothing. Nowhere near the ashtray on either side, and the factory diagrams I've looked at seems to place it somewhere behind the instrument cluster

Odometer screen is now blank, but will come back on with removal of the #4 instrument cluster fuse on side driver dash, but of course nothing else on the dash will work without the fuse, which the legend states also powers BCM, along with a few other fuses that the circuits are controlled by the BCM

I performed a OEM enhanced scan and found 21 codes, some of which began with a U which are related to the BCM. I figured they were from driving the vehicle without the #4 / #7 fuses and erase them, which resulted in my scanner saying erase successful - but then showing 41 codes, none of which began with U, mostly every powertrain code there is , none of which would show up on a regular OBD scan, which I completely don't understand

Truck now seems to be glitching more than ever, and having a negative effect on driving

I'm getting more and more confused with every step I take, any ideas or suggestions would be greatly appreciated

Customer has been looking up lots of videos and stuff on her own. She found one today that said check the TBC fuse under hood, and replace it even if it looks good

It's another fuse that's linked to the BCM

She tried that, and says all of the problems went away - even the CEL that was on went off after a short drive

Fingers crossed it was as simple as a fix like that. After I've spent 8 hours trying to chase down bad wiring

From what I'm told, that fuse is a common issue among 99 - 06 GM

. And the fuse will look fine, but somehow a replacement provides to fix