Cold Defrost and warm engine on 2007 Ford Ranger

During my work commute the engine temp reads to the middle but the defrost air comes out cold. a week ago I took it to JiffyLube and they did replace the air filter. Could a small hose not be connected? Thanks!

1 answer
do you have hot air anywhere in the car. if you get it on the floor and dash vents tht would leave to believe that you have a diffuser motor out or the diffuser box door has come loose or jammed