doors vibrate open or close How did you fix this problem?

 

Guess you are speaking of the vent doors. I took the bolts out of mine and replaced the nut on themwith a wing nut with teflon liner. Seems to work so far. You are suppose to be able to tighten the nut on the bolt that is there but I never could get it to tighten correctly. The wing nut is just easier to get to and tighten.

 

Tighten them up a bit, they loosen over time. You want there to be a little resistence when you move them with your hands.