Alright, so I'm kind of stumped here. I was having trouble getting the fan to direct the air flow to my vents. I replaced the mode door actuator and it seems to be working properly. The linkages are all intact and appear to be functioning the doors. When I switch from Defrost to floor to vent everything functions until you get to vent then the flow is directed to the side vents (the ones that come out on the sides by the driver and passenger window). Can anyone think of anything that it might be? I've functioned the mode door manually with the actuator off and it does the same thing.

 

When it goes from Floor to Vent, is air also still coming out thru Floor? If so, then I think a door is physically getting stuck in the Floor position. That would explain Side Vent only condition (I think).

 

I took the floor ducts off so I could watch it and the bottom one functions properly. There's another one up above it that functions through the linkages when the bottom one functions and even though I cant see it, it appears to function properly. I've tried it both ways by functioning it manually by hand and it does the same thing as when you switch it with the controls.

 

Oh and it's a 1996 Chevrolet C1500 with the 5.7.