Tons of info and pics on this subject already but this is my experience cleaning the engine bay upper driver and passenger side ground points.

I did this to see if by chance it would fix my headlight motors not working, and it did not, and the fuses involved all test good, so it is now almost certainly the HCM headlight control module that needs replaced. 130K miles, parked outdoors often, driven in every kind of weather so no surprise there. Zip Corvette calls is a 'headlight motor module' which they stock for $154 https://www.zip-corvette.com/88-04-h...or-module.html (thank you loufernh of Maryland for that info!)

1. I didn't remove any hoses, cables, etc. I was able to remove the 10mm nuts from both bolts with a deep 10mm socket and ratchet.
2. Once I wiggled the two connectors off each (one is the black plastic multi wire plug, the other just an eye connector with 2 black wires connected), I was able to sand/wire brush everything to a shiny clean, including the base of the bolt that comes up out of the frame area. They were almost black, the area was filthy, even a cig butt down in there (not mine!).
3. I unclipped the grey plastic piece by pushing in it's small gray tab on one end of the black plastic module, then with a screwdriver working around it's edges to free it up, it just pulls completely off at that point. It's open on one end, easy to remove and to replace when ready.
4. I sprayed contact cleaner in the black housing at the connectors and worked them a bit, not a pro job, I did not remove and clean each one.
5. Reassembled and tested, still no headlights but a for sure gain of 5hp per connection. For sure.

 

It does not look like you disassembled the ground pack itself.

Check Bill Curlee's post in stickey. https://www.corvetteforum.com/forums...tion-long.html

May or may not solve the problem but there is more to do cleaning grounds.

 

Yep exactly what I said. Jeez.

“ I sprayed contact cleaner in the black housing at the connectors and worked them a bit, not a pro job, I did not remove and clean each one”

 

I like the cigarette butt!