in a 98 accord. Starting to have the problem where the AC controls get stuck on defrost and will not change to the vents. The lights shows output on the vents but the air continues to flow through the defrost outakes on top of the dash.

Any idea the problem/fix?

Thanks.

 

There is a vent selection motor (electrical) which moves the door to select various vent outlets. It has likely failed or failing. You will need a shop manual to find the component, test, and replace. You may be able to use the 94-97 Accord manual download from Online Manuals post in DIY section.

good luck