Floor vent HVAC - My floor vent has not worked for 2 years and my toes are getting cold. I can use any other mode and it works perfectly. My ...

My floor vent has not worked for 2 years and my toes are getting cold. I can use any other mode and it works perfectly. My question is should I look at the actuator or maybe blockage? Where should i access the duct to find the door? i have had the dash down that far 3 times and never found anything obvious.

Any advice would be appreciated!
Thanks Steve

Something to try

1) Unplug HVAC fuse for 10-30 seconds
2) Start truck
3) A/C comes out defrost - wait about 10 to 15 secs. If not, cycle the distribution **** ( for lack of a better term), the one that selects which vent it comes out of. I had to do this before it would cycle.
4) A/C then starts coming out the floor vents for about 5 seconds
5) A/C then starts coming out the dash vents.
6) While the A/C is coming out the dash vents, turn A/C OFF (otherwise it cycles back to defrost for good).
7) Turn truck OFF
8) Restart truck and it should work fine

(found on the net)