2011 Yukon Denali: Driver side seat belt buckle would not latch; tried cleaning and lubing with silicone spray, no fix. I was totally unable to get the wire harness unlatched, as working totally blind, what a ridiculous piece of "engineering", that push an unseen latch while pulling apart, between the seat and the console. Harness could've been engineered/manufactured to have the disconnect near the part near the attaching hole; Thanks, GM !!!!

Anyway, I found that if Mrs. Cusser could insert the metal latch then push the red release button on the buckle about 1/8" down, then the buckle would catch and operate like it should.

 

Buckle still working fine, using the workaround.

Fixed its left fog light (Mrs. Cusser didn't know it even had fog lights), was just a dirty female connector where it plugged into the fog bulb. I had tested the bulb itself, had noticed the harness for it just hanging free, and it had an aftermarket part label on it. Anyway, stuck 2 paper clips into that connector to test for voltage (which it had) and this time it worked after connecting it. Good, had bugged me !