Old zippers can wear away part of the pull so that it jams in a sideways position. It can still work, but it's awkward to use. Trying to zip this old fleece jacket has become a hassle. I finally got tired of fighting to get the pull oriented while working in an unheated house. With wire cutters within reach, I just cut the pull off.
Oops.... this is a zipper with a lock. No zipper pull = no movement. Errrg!
Step 1: # 14 Wire and Little Blue Nut.
But wait! I also have rolls of #14 wire at hand and a container of little wire nuts.
OK... cut a little piece of wire.... thread it through the zipper thing... bend it ....and twist on the nut FIRMLY.
Step 2: Ta Da... Functional Zipper!
It's now been through the washer and drier a couple of times with no problems.