I posted elsewhere in this forum about my experience checking ground G106 when chasing repeat charging system issues. Ground G106 is a ring terminal mounted on the fender between the hood strut and windshield on the driver's side. This ring terminal - according to the Service Manual - fans out to about 20 different electrical systems on the truck. I suspect - cannot confirm - that this is also the main ground for the TIPM.
In the "Underhood Grounds" picture I've attached, you can see the bolted connection on the left side of the picture. As seen in the "G106 Fender Detail" picture, there's two oval holes above the bolt. The white on the bolt is white lithium grease that I applied when I unbolted, cleaned, and reassembled this connection; since my initial cleaning, I've added an 8 AWG cable from this bolted connection back to battery negative.
I'm not going to promise that this will fix all issues; I will opine that this ground should have been a cable return to battery negative because of the holes punched into the fender above the bolted joint. Corrosion on the bolt's threads will cause what my former colleagues and I called a "ground shift" - that is, the resistance across the corrosion is enough to cause "ground" to be "ground + some unknown positive voltage less than 12 volts." (In my case, that ground shift was about 2.6 volts with the engine running.)
Even if this does not fix your issues, it will ensure that this ground is not causing additional problems.
