Hi all new here. I have a 1994 F150 XLT with the 5.0L motor. I'm experiencing a problem that in one form or another is problematic for fords it seems. My heater and AC works ok but can't get it to switch to floor for heat. Vents and defrost work ok but also the mix setting doesn't blend between floor and defrost either sill all air flow goes to defrost very little if any goes to floor on mix.
I'cer something about a blend door isn't this for bending hot and cold not between floor and defrost.
i haven't read or found anything on my exact problem. This is a one owner vehicle from new so shouldn't have had a lot of people monkeying around with anything and the origami owner a personal friend was very facetious with things so...
I'm stumped for now?
Suggestions?
Thanks

 

it is mostly a vacuum system, with the ***** on the dash routing the appropriate vacuum one way or another or not.

There are some diagrams in the alldata/shopkey pro systems that diagram the flow for floor, defrost, etc.

Following the lines or looking for damage in those lines would be the first step in sorting this. Especially under the hood and where the vacuum transitions to the heater control stuff and then in to the back of the glove box and over to the dash switches.

something like this for the 1996

not sure what the exact differences are between these years





 

Look for white vacuum line on passenger side under hood near firewall. could be broken or leaking.