Surely my query has been answer many times here, but deang if I can find it.
I have a 1999 Ford F350 7.4 Liter Diesel turbo pickup; the vehicle's defrost setting allows air to be vented, but when I try to vent air to the foot area or the chest area nothing comes out. I assume something is blocked, and that this happens often to people.
Is there a way to fix this? If you let me know the secret I will be ever grateful.
David