[hatzie]

Originally Posted by TKCR

You’ll never get them to “take hold” by yanking on them. Doesn’t matter how hard, or how fast. Our belts don’t work that way. They only have ELR, which means they will lock when you brakes are hit hard.
The ALR feature, yanking on the belts and they “take hold”, that didn’t start until much later.
I really hate to think of all the belts that got tossed, because people thought they didn’t work because of the yanking on the belt theory. I know I get a lot of people that think their belts don’t work, when they do.
If you want to test it. Take the truck out some place where you can do this safely. When you are at driving speeds, hit the brakes hard. The belt should lock up. Now there are times that they may not, because the pendulum or counter balance can not swing, because of all the gunk build up in the retractors. I have had a few belts like that. There was so much hair balls and string wrapped around the counter balance it couldn’t even move. Another time, I had mud wasp nest all up inside the retractor casings.

That's some very important information about locking seatbelts in this generation GM vehicles.