Check for fabric, thread, or debris caught in the zipper teeth
Gently pull the zipper slider back and forth to free any obstruction
Use a pencil, soap, or zipper lubricant on the teeth if the zipper is stuck
Align both sides of the zipper carefully before pulling it up
If the slider is loose, squeeze it slightly with pliers to tighten it
If the slider is bent or broken, replace the slider
If teeth are missing or damaged, replace the entire zipper
If the zipper separates after closing, replace the slider or zipper
If the pull tab is broken, attach a key ring or paper clip as a temporary pull
Sew any loose fabric near the zipper away from the teeth
Test the zipper several times after each fix
Take the coat to a tailor or repair shop if the zipper cannot be fixed at home