theres a place on line that rebuilds them.

first take it out, if you see white corrosion at the bolts or the edges of the box, clean that up and the car body, and re install it.

some you can open up and clean further. some you cant. its a 50/50 shot if cleaning it will work. but its free.

dont forget to clean the plug under the drivers seat, and the end of the clock spring under the dash. its also yellow. ( any plug you find thats yellow is for the air bags)