Buttons will not stay down when pushed in. What should I look for to fix? Thanks

 

This is the top of the heater control - if none of your buttons stay depressed, you may have broken or unhooked the return spring there in the center. I’m not fully schooled on the operations of this piece either, as three of mine will not stay depressed while off the car like this. I haven’t looked into it in depth yet. Hope this gets you going in the right direction. You also might check to see if the unit is full of fallen insulation. This one was completely jammed with that.

 

Before doing anything drastic including dropping the dash, I might suggest spaying a solvent/lubricant such as WD-40 into the mechanism - try spraying in different directions on top of the different buttons and then working them one at a time. Maybe something's stuck in position or gummed up. Good luck.