For the last two years my trucks had trickling air flow from the vents and almost no hot air. I’ve never been willing to rip the dash out but I’m not doing another winter without heat. Brought it to the mechanic a couple days ago. They said it needed a new heater core and a new fan. $1300. Decided I’m atleast gonna try to flush the core first which he wouldn’t do. Did that yesterday. Blew it out with a compressor, filled it with cleaner and flushed it with a hose. Worked great. Heat was trickling out of the vents. Today I planned on figuring out the airflow problem. Assumed I’d be pulling the whole dash apart. Once I pulled the glove box out I immediately saw the problem. Napkins from the glovebox got sucked into the intake grill above the cabin filter. Pulled them out and the airs cranking. Two years of no air and it was because of a napkin. saved $1300 And the rest of my day.