Hi guys, just got done doing a thermostat in the old 87 and when I went to turn the heat on, I have the def function, the heat function, but when I kick it to vent it stays coming out the bottom. I’m guessing a door is stuck or something. Where can I start looking? I hope I don’t have to try to take that dash off. Any help would be great. I did look through some old threads and couldn’t really find what I was looking for. Thanks