Ground Lug location 2005 Tahoe

[alamantia]

My rear wiper and defroster wouldn’t work this morning on my truck. The lights on the switches lit up. I checked the fuses and they were ok. I am going to assume they both share a common ground lug. I am going to take apart the tailgate when I get home tonight and inspect this lug. The only problem is. I don’t know where this lug is located. Any ideas where it may be?

 

[wreedps]

Ever figure this out?