The A/C cools fine but the (underdash) controls change the air to the
defrost position instead of out the dash vents. It makes "groaning"
noises like it is trying to switch back to the dash vents but it
rarely does. I've looked for a vacuum leak under the hood and had an
A/C shop check too. Found no leaks. I wasn't able to check up under
the dash though.
Any ideas?
